MRI-Based Septal Curvature Ratio for Differentiating Right Ventricular Pressure and Volume Overload in Repaired Tetralogy of Fallot and Shunt-Associated Pulmonary Hypertension

MRI-Based Septal Curvature Ratio for Differentiating Right Ventricular Pressure and Volume Overload in Repaired Tetralogy of Fallot and Shunt-Associated Pulmonary Hypertension | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article MRI-Based Septal Curvature Ratio for Differentiating Right Ventricular Pressure and Volume Overload in Repaired Tetralogy of Fallot and Shunt-Associated Pulmonary Hypertension Ilker Kemal Yucel, Kevser Banu Kose, İsa Özyılmaz, Muhammed Faruk Kazanbaş, and 8 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7220176/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Cardiac MRI-derived septal-to-free wall curvature ratio is a non-invasive marker to evaluate right ventricular pressure and pulmonary hypertension. Objective: To investigate whether the septal-to-free wall curvature ratio measured by cardiac MRI can differentiate between right ventricle pressure and volume overload in different right ventricle overload conditions. Materials and Methods: Between 2020 and 2025, 149 participants were classified into four groups: controls ( n =21), patients repaired with ( n =55) and without ( n =52) right ventricular outflow tract stenosis, and patients with left-to-right shunt and pulmonary hypertension ( n =21), retrospectively. The association of the septal-to-free wall curvature ratio, calculated using MATLAB, with functional parameters and group differences was analyzed. Results: Significant differences in septal-to-free wall curvature and right-to-left ventricular volume ratios were found across groups (P<0.05). The curvature ratio was lowest in the left-to-right shunt lesions with pulmonary hypertension (0.610 ± 0.238), followed by the tetralogy of Fallot with stenosis group (0.670 ± 0.238). The curvature ratio showed moderate-to-strong correlations with right-to-left ventricular end-diastolic (r = –0.59) and stroke volume ratios (r = –0.54). ROC analysis showed excellent diagnostic performance in detecting pulmonary hypertension (AUC=0.921) and strong discriminatory ability in tetralogy of Fallot without stenosis (AUC=0.877), while moderate performance was observed in tetralogy of Fallot with stenosis (AUC=0.777). Significant negative correlations were identified between curvature ratio and right ventricle volumes and right-to-left ventricle ratios, while a positive correlation was found with right ventricle ejection fraction in the tetralogy of Fallot subgroup. Conclusion: Cardiac MRI-derived septal-to-free wall curvature and volume ratios offer valuable non-invasive markers for distinguishing right ventricular pressure and volume overload. Pediatric Tetralogy of Fallot Pulmonary Hypertension Septal-to-Free Wall Curvature Ratio Cardiac Magnetic Resonance Imaging (MRI) Figures Figure 1 Figure 2 Figure 3 Figure 4 INTRODUCTION Tetralogy of Fallot is the most common cyanotic congenital heart disease and usually undergoes early complete repair with ventricular septal defect closure and relief of right ventricular outflow tract obstruction ( 1 ). However, despite the success of this approach in improving long-term survival, it may lead to chronic complications, including residual right ventricular outflow tract obstruction and/or pulmonary regurgitation due to right ventricular outflow tract augmentation ( 1 ). Right ventricular remodeling and dysfunction secondary to volume or pressure overload are frequently seen in several congenital heart diseases, either in tetralogy of Fallot and left-to-right shunt lesions ( 2 , 3 ). In repaired tetralogy of Fallot, residual pulmonary regurgitation results in right ventricular dilatation, secondary tricuspid regurgitation, and progressive right ventricular volume overload ( 3 , 4 ). On the other hand, residual right ventricular outflow tract stenosis and associated pressure overload are accepted as independent predictors for adverse outcome ( 5 , 6 ). Right ventricular volume/pressure overload significantly alters the shape and function of the interventricular septum and often causes interventricular septal flattening or leftward septal bowing ( 6 – 8 ). Earlier studies have shown that the end-systolic flattening of the interventricular septum primarily occurs because of right ventricular pressure overload ( 9 , 10 ). Moreover, severe septal flattening is often considered to be associated with an unfavorable prognosis in pulmonary hypertension ( 11 – 13 ). Although invasive hemodynamic assessment with cardiac catheterization remains the gold standard for diagnosis of pulmonary hypertension, cardiac magnetic resonance imaging (MRI)-derived parameters are widely used for non-invasive assessment of pulmonary hypertension ( 14 – 16 ). The septal-to-free wall curvature ratio, derived by dividing the curvatures of the septum and the left ventricular free wall, has been defined as a quantitative marker of septal flattening, indicating a marker of systolic right ventricular hypertension or increased transseptal pressure differences ( 17 – 19 ). This ratio has demonstrated a strong correlation with invasive hemodynamic measurements and has shown high diagnostic accuracy in identifying pulmonary hypertension in both adult and pediatric cohorts ( 13 , 18 , 19 – 21 ). The use of cardiac MRI has expanded the ability to non-invasively quantify these morphological changes with high reproducibility and spatial resolution ( 17 – 21 ). However, the septal-to-free wall curvature ratio across different right ventricular loading patterns in congenital heart disease, such as repaired tetralogy of Fallot (with or without right ventricular outflow tract stenosis) and left-to-right shunt lesions, has not been evaluated before. This study aims to investigate the non-invasive differentiation of right ventricle remodeling across the septal-to-free wall curvature ratio between congenital heart disease subgroups in pediatric age and evaluate the relationship of septal-to-free wall curvature ratio with cardiac MRI parameters, including ventricular volume ratios. MATERIALS AND METHODS This retrospective study received ethical approval from the Institutional Review Board (Reference No: E-10840098-202.3.02-3438). All procedures were conducted following the ethical standards of the Declaration of Helsinki. Written informed consent for cardiac MRI was obtained from all participants, and parents or legal guardians for individuals under 18 years of age, before the examination. Study Population We retrospectively reviewed the clinical and imaging data of 256 patients who underwent cardiac MRI between 2020 and 2025. A total of 128 patients and 21 healthy controls were included in the study and categorized into four groups based on clinical and imaging characteristics. Control group (n = 21) : Healthy individuals without congenital heart disease. No evidence of pulmonary hypertension and right ventricular outflow tract stenosis. Tetralogy of Fallot without stenosis (n = 52) : Patients with surgically repaired tetralogy of Fallot without residual left-to-right shunt and right ventricular outflow tract stenosis. These patients had moderate-to-severe pulmonary regurgitation measured by cardiac MRI. Tetralogy of Fallot with stenosis (n = 55) : Patients with surgically repaired tetralogy of Fallot with moderate-to-severe right ventricular outflow tract stenosis. These patients had moderate-to-severe pulmonary regurgitation measured by cardiac MRI. Left-to-right shunt with pulmonary hypertension group (n = 21) : Patients with significant left-to-right shunting lesions, including atrial septal defect (n = 6), ventricular septal defect (n = 7), partial anomalous pulmonary venous connection (n = 6), and aortopulmonary window (n = 2) with pulmonary hypertension. These patients had no evidence of right ventricular outflow tract stenosis. Group classification for healthy control group patients with tetralogy of Fallot was based on noninvasive imaging modality and echocardiography-derived parameters, since right heart catheterization is not routinely performed for patients with Tetralogy of Fallot and is not indicated in the control group. Right ventricular outflow tract stenosis is defined as increased right ventricular pressure in repaired tetralogy of Fallot patients. Right ventricular-pulmonary artery peak-to-peak systolic pressure higher than 40 mmHg is considered increased right ventricular systolic pressure ( 22 ). Right ventricular systolic pressure was estimated by continuous-wave Doppler echocardiography using the peak tricuspid regurgitant jet velocity, applying the modified Bernoulli equation. Right Ventricular Systolic Pressure = 4 × (peak tricuspid regurgitation velocity)² + estimated right atrial pressure , with the right atrial pressure assumed to be 5 mmHg ( 23 ). In patients with left-to-right shunt lesions and pulmonary hypertension, pulmonary artery pressure was retrospectively obtained from right heart catheterization records. Pulmonary hypertension was defined based on catheter-based diagnoses as mean pulmonary artery pressure > 25 mmHg with pulmonary capillary wedge pressure < 15 mmHg ( 22 , 24 ). Pulmonary-to-systemic flow ratio (Qp/Qs) was calculated using cardiac MRI phase-contrast imaging. A Qp/Qs ratio higher than 1.5 was considered indicative of a significant shunt ( 25 ). Inclusion criteria for the patient cohort were: 1) patients with a left-to-right shunt who had right heart catheterization with a diagnosis of pulmonary hypertension confirmed by right heart catheterization; 2) individuals with previously repaired tetralogy of Fallot who were referred to our center for routine follow-up. Patients were excluded if they had: 1) right heart catheterization or echocardiography performed more than three months before or after cardiac MRI; 2) left-sided cardiac disease or pulmonary disease; 3) cardiac MRI images of insufficient quality for analysis due to motion artifacts, poor breath-hold performance, and and arrhythmias; 4) patients with right ventricular outflow gradient gradient between 30–40 mmHg were excluded to ensure distinct group separation. Demographic information, including sex, age at the time of surgical repair, as well as age, weight, and height at the time of cardiac MRI, data of echocardiography, and right heart catheterization, were also obtained from the institutional electronic medical records. Cardiac MRI Examination and Image Analysis All Cardiac MRI examinations were performed using a 1.5 Tesla scanner (Avanto; Siemens Healthineers, Erlangen, Germany and 450W; Ingenia (Philips Healthcare, Best, the Netherlands) with a 32-channel phased-array abdominal coil with electrocardiographic gating. The imaging protocol included cine sequences for biventricular volumetric and functional analysis, as well as through-plane phase-contrast imaging for pulmonary artery flow quantification. Steady-state free precession cine images were acquired in contiguous short-axis slices covering the entire ventricles, along with standard long-axis views. Each set of images was acquired with retrospective gating. The scanning parameters for the Avanto (Siemens Healthineers, Erlangen, Germany) were as follows: repetition time = 3.2 ms, echo time = 1.6 ms, flip angle = 60°, field of view = 275 × 340 mm, matrix size = 224 × 256, slice thickness = 8 mm, slice gap = 0 mm. The scanning parameters for the Ingenia (Philips Healthcare, Best, the Netherlands) were as follows: TR 3.6 ms; TE 1.5 ms; flip-angle 60°; bandwidth ± 90 kHz; matrix 192 × 192; FOV 350 mm; NEX 1; slice thickness 8 mm; gap 0 mm. Phase-contrast imaging was performed perpendicular to the main pulmonary artery just distal to the pulmonary valve. The optimal velocity encoding value of the pulmonary artery was calculated by the Bernoulli equation, reported gradients in the echocardiography report ( 8 ). The applied parameters for the phase contrast imaging sequence of the Avanto (Siemens Healthineers, Erlangen, Germany) were as follows: TR 31.8 ms; TE 2.9 ms; flip-angle 30°; bandwidth ± 60 kHz; matrix 192 × 160; FOV 350 mm; NEX 1; slice thickness 6 mm. The scanning parameters for the Ingenia (Philips Healthcare, Best, the Netherlands) were as follows: TR 5 ms; TE 3 ms; flip-angle 20°; bandwidth ± 60 kHz; matrix 192 × 160; FOV 350 mm; NEX 1; slice thickness 6 mm. The scanning parameters. All the examinations were acquired with retrospective electrocardiogram gating and 20–25 reconstructed cardiac phases according to the heart rate. All cardiac MRI evaluations were performed using a software (IntelliSpace Portal 11.2, Philips Healthcare, Best, The Netherlands) by at least ten years of experience, blinded to patient information. Ventricular volume, function, pulmonary regurgitation, and Qp/Qs are calculated according to the recommendations ( 26 , 27 ). All measurement was performed automatically and manually corrected. Papillary muscles were included in the blood pool. Volumes were indexed to body surface area. Septal-to-free wall curvature ratio was measured on mid-ventricular short-axis cine images acquired using steady-state free precession sequences at end-systole. Measurements were performed using custom MATLAB scripts (MathWorks, Natick, MA, USA). Best-fit curves were applied to the manually traced contours of the interventricular septum and the corresponding free wall. The perimeter (C) of each contour was calculated. Assuming circular approximation, the radius of curvature (R) was then derived using the formula R = C/2π ( π ≈ 3.1416). Septal curvature was expressed as the reciprocal of the radius (1/R) to obtain a dimensionless curvature value. The septal-to-free wall curvature ratio was computed by dividing the septal curvature (1/R septum) by the free wall curvature (1/R free wall). End-systole as the frame just before mitral valve opening. A rightward curvature was accepted as a positive value, and a value close to 0 indicated an almost flat; a negative value indicated a leftward curvature. STATISTICAL ANALYSIS Statistical analyses were conducted using SPSS version 20.0 (IBM, Armonk, NY, USA). Descriptive statistics for continuous variables were presented as mean ± standard deviation and median with interquartile range (IQR: 25th–75th percentiles), where appropriate. The normality of data distribution was assessed using the Shapiro–Wilk test. Depending on the distribution, either one-way analysis of variance [ANOVA] or Kruskal–Wallis test methods were applied to compare differences among the four independent groups. For parameters with statistically significant overall differences (p < 0.05), post hoc pairwise comparisons were performed using Tukey’s Honest Significant Difference test or Dunn’s test, respectively. Pearson or Spearman correlation coefficients were used to evaluate the relationships between septal curvature ratio and cardiac MRI parameters, based on data distribution. Receiver operating characteristic (ROC) analyses were conducted for septal-to-free wall curvature ratio, right-to-left ventricular end-diastolic volume ratio, and right-to-left ventricular stroke volume ratio to assess their diagnostic performance in distinguishing each patient group from healthy controls. Area under the curve (AUC), optimal cut-off values, sensitivity, and specificity were reported. A P-value < 0.05 was considered statistically significant for all tests. Results A total of 149 participants were included and classified into four groups: patients with pulmonary hypertension due to significant left-to-right shunt ( n = 21), postoperative patients without stenosis ( n = 52), with stenosis ( n = 55), and a healthy control group ( n = 21). No significant differences were found in age, body surface area ( P = 0.673 and P = 0783, respectively). Among the patient population ( n = 128), the mean age was 12.85 ± 3.92 years, and the median body surface area was 1.50 m² [ IQR :1.30–1.80]. The mean right ventricular end-diastolic volume index was 158.03 ± 48.46 mL/m², with a median of 156.00 mL/m². The mean right ventricular ejection fraction was 43.98 ± 7.88% and the left ventricular ejection fraction was 49.88 ± 7.52%. The pulmonary regurgitation fraction was highest in postoperative patients with stenosis (38%±10%), followed by patients with significant left-to-right shunt (22 ± 8%) and postoperative tetralogy of Fallot patients without stenosis (15 ± 5%). No measurable regurgitation was observed in the control group. In patients with significant left-to-right shunting, the mean Qp/Qs ratio was 2.1 ± 0.5, indicating a substantial shunt, and the mean pulmonary artery pressure was 42 ± 8 mmHg, reflecting mild-to-moderate pulmonary hypertension. Significant differences were observed across the four groups among right ventricular cardiac MRI parameters ( P < 0.05). Left ventricular cardiac MRI parameters in terms of left ventricular end-diastolic and stroke volume index also demonstrated statistically significant differences ( P = 0.001, P < 0.0001, respectively). Detailed distributions of the conventional cardiac MRI parameters among groups are presented in Table 1 . Table 1 Baseline Demographic and Cardiac MRI Parameters Among Study Groups Parameter Control (n = 21) Left-to-Right Shunt with PHT (n = 21) TOF with Stenosis (n = 55) TOF without Stenosis (n = 52) p-value BSA (m²) 1.72 ± 0.30 1.60 ± 0.58 1.73 ± 1.76 3.91 ± 18.28 0.783 Age (years) 13.50 ± 3.12 11.50 ± 5.55 13.14 ± 3.03 12.81 ± 4.37 0.673 RV-EDVI 90.67 ± 18.75 122.19 ± 65.43 156.35 ± 39.24 173.31 ± 41.74 < 0.0001 RV-ESVI 46.92 ± 11.77 62.71 ± 44.96 89.85 ± 29.40 101.64 ± 30.67 < 0.0001 RV-SVI 44.58 ± 9.58 59.67 ± 26.05 66.21 ± 17.29 71.33 ± 17.32 0.001 RV-EF (%) 48.33 ± 7.13 50.71 ± 9.34 43.23 ± 6.89 42.13 ± 6.88 0.011 LV-EDVI 89.79 ± 10.45 85.48 ± 44.37 88.50 ± 13.08 92.85 ± 19.76 0.001 LV-ESVI 41.21 ± 7.68 43.71 ± 33.16 45.62 ± 9.88 46.98 ± 12.95 0.175 LV-SVI 48.64 ± 7.09 43.24 ± 17.31 42.85 ± 6.71 45.93 ± 10.43 < 0.0001 LV-EF (%) 54.21 ± 5.99 53.29 ± 12.04 48.71 ± 5.72 49.69 ± 6.52 0.233 Data are presented as mean ± standard deviation or median (interquartile range) as appropriate. p-values derived from one-way ANOVA or Kruskal–Wallis test as applicable. Significant differences were found among the four groups regarding septal-to-free wall curvature ( P = 0.0003), right-to-left ventricular end-diastolic volume ( P < 0.0001), and right-to-left ventricular stroke volume (P < 0.0001) ratios. Detailed distributions of the cardiac MRI-derived parameter among groups are presented in Table 2 and Fig. 2 . Table 2 Comparison of Septal-to-Free Wall Curvature and Right-to-Left Ventricular Volume Ratio Among Study Groups Parameter Control (n = 21) Left-to-Right Shunt with PHT (n = 21) TOF with Stenosis (n = 55) TOF without Stenosis (n = 52) p-value Septal-to-Free Wall Curvature Ratio 0.903 ± 0.054 0.610 ± 0.238 0.694 ± 0.175 0.742 ± 0.206 0.0003 Right-to-Left Ventricular EDV Ratio 0.907 ± 0.309 1.681 ± 0.923 1.780 ± 0.396 1.811 [1.531–1.990] 1.882 ± 0.316 < 0.0001 Right-to-Left Ventricular SV Ratio 0.838 ± 0.288 1.508 ± 0.704 1.561 ± 0.369 1.543 1.589 ± 0.369 < 0.0001 Data are presented as mean ± standard deviation or median (interquartile range) as appropriate. p-values derived from one-way ANOVA or Kruskal–Wallis test as applicable. The septal-to-free wall curvature ratio was evaluated for its association with cardiac MRI measurements in each group. In patients with repaired tetralogy of Fallot, the septal-to-free wall curvature ratio demonstrated significant negative correlations with right ventricular end-diastolic volume ( r = − 0.353, P = 0.0103), right ventricular end-systolic volume (r = − 0.428, p = 0.0015), and the right-to-left ventricular end-diastolic volume ratio ( r = − 0.367, P = 0.0075). A significant positive correlation was observed with right ventricular ejection fraction ( r = 0.413, p = 0.0023) (Fig. 3 ). Although a moderate negative correlation was observed between septal-to-free wall curvature ratio and right ventricular ejection fraction in the pulmonary hypertension with left-to-right shunt group ( r = − 0.423), this did not reach statistical significance ( P = 0.0635). No significant correlations were identified between septal curvature and cardiac parameters in the pulmonary stenosis group. Correlation between the septal-to-free wall curvature ratio and cardiac MRI parameters between study cohorts is presented in Table 3 . Table 3 Correlation between the septal-to-free wall curvature ratio and cardiac magnetic resonance imaging parameters between study cohorts Parameters Control (n = 21) Left-to-Right Shunt with PHT (n = 21) TOF with Stenosis (n = 55) TOF without Stenosis (n = 52) p-value r-value p-value r-value p-value r-value p-value r-value RV-EDVI 0.757 0.101 0.688 0.096 0.466 0.114 0.011* -0.353 RV-ESVI 0.768 0.095 0.364 0.214 0.476 0.098 0.001* -0.428 RV-SVI 0.818 0.074 0.570 -0.135 0.650 0.062 0.399 -0.119 RV-EF 0.766 0.096 0.063 -0.423 0.990 0.002 0.002* 0.413 LV-EDVI 0.305 0.295 0.963 0.011 0.895 -0.018 0.914 0.015 LV-ESVI 0.111 0.444 0.789 -0.064 0.844 0.027 0.790 -0.038 LV SVI 0.877 -0.045 0.990 -0.003 0.652 -0.062 0.571 0.081 LV-EF 0.155 -0.401 0.744 0.078 0.438 -0.107 0.680 0.059 Right-to-Left Ventricular EDV Ratio 0.327 0.295 0.769 -0.071 0.379 0.121 0.007* -0.367 Right-to-Left Ventricular SV Ratio 0.186 0.391 0.611 -0.121 0.454 0.103 0.342 -0.134 P-values indicate the significance level of differences across groups based on one-way ANOVA with Tukey post-hoc test. Receiver operating characteristic (ROC) analysis confirmed the diagnostic utility of the septal-to-free wall curvature ratio in distinguishing patient groups from healthy controls (Fig. 4 ). The septal-to-free wall curvature ratio showed high accuracy in the left-to-right shunt with pulmonary hypertension group (AUC = 0.921; sensitivity = 80.0%; specificity = 95.2%) and tetralogy of Fallot without stenosis (AUC = 0.877; sensitivity = 73.1%; specificity = 95.2%) and moderate performance in tetralogy of Fallot with stenosis (AUC = 0.777; sensitivity = 63.6%; specificity = 100.0%). The right-to-left ventricular end-diastolic volume index ratio provided high accuracy in tetralogy of Fallot without stenosis (AUC = 0.974; sensitivity = 94.2%; specificity = 100.0%), but performed less effectively in the pulmonary hypertension group (AUC = 0.694; sensitivity = 52.4%; specificity = 100.0%). Similarly, the right-to-left ventricular stroke volume index ratio also demonstrated excellent diagnostic power, particularly in tetralogy of Fallot without stenosis (AUC = 0.958; sensitivity = 86.5%; specificity = 100.0%) and was moderately effective in the pulmonary hypertension group (AUC = 0.790; sensitivity = 81.0%; specificity = 83.3%). Discussion This study demonstrated that the septal-to-free wall curvature ratio is a quantitative non-invasive marker of interventricular septal flattening, which differs significantly between different right ventricular loading patterns. The septal-to-free wall curvature ratio value was significantly reduced in both pressure and volume overload conditions, with the lowest values observed in the left-to-right shunt with pulmonary hypertension group. These findings would support that septal deformation reflects distinct right ventricle loading patterns and may serve as a non-invasive indicator of the nature of the disease. Additionally, the septal-to-free wall curvature ratio showed significant correlations with right ventricular volume, ejection fraction, and right-to-left ventricular end-diastolic volume ratio. Cardiac MRI remains the gold standard for non-invasive, reproducible assessment of cardiac morphology and function, particularly for the right ventricle ( 1 , 3 , 5 ). Among cardiac MRI-derived markers, the septal-to-free wall curvature ratio has been recognized as a reliable measurement of right ventricle pressure and volume overload ( 15 , 16 – 21 ). Previous studies have reported strong correlations between the septal-to-free wall curvature ratio and invasively measured pulmonary and right ventricle pressures ( 18 – 20 ). Dellegrottaglie et al. ( 20 ) demonstrated a significant correlation between curvature ratio and right ventricular systolic pressure measured by right heart catheterization, while Roeleveld et al. ( 13 ) confirmed a linear relationship between systolic pulmonary arterial pressure and the degree of leftward septal bowing or flattening. Similarly, Pandya et al. ( 18 ) demonstrated that the septal-to-free wall curvature ratio reflects a reliable non-invasive indicator of mean pulmonary artery pressure and pulmonary vascular resistance in children with pulmonary hypertension. Consistent with these studies, our findings revealed the septal-to-free wall curvature ratio as a sensitive marker of right-sided loading conditions. Importantly, while prior studies focused predominantly on isolated pulmonary hypertension ( 13 , 18 – 20 ), our study is the first to compare the septal-to-free wall curvature ratio across different congenital heart disease subgroups in a pediatric population. Importantly, our study extends existing knowledge by systematically comparing septal-to-free wall curvature ratio across distinct congenital subgroups with varying degrees and types of right ventricle loading. In our study, the lowest value of septal-to-free wall curvature ratio were found in the left-to-right shunt-associated pulmonary hypertension group, which appears to reflect the combined effects of elevated pulmonary pressures, increased flow, and vascular remodeling. This group demonstrated both pressure and volume overload, leading to more pronounced septal distortion, likely due to increased right ventricle wall stress ( 8 ). In contrast, repaired tetralogy of Fallot with residual stenosis group demonstrated more significant septal flattening compared to the non-stenotic tetralogy of Fallot, reflecting predominant right ventricular pressure overload. Despite a relatively preserved right ventricular ejection fraction, this group also had the markedly elevated pulmonary regurgitation fraction (38% ± 10%), suggesting a dual burden of pressure and volume overload. These findings are consistent with those of Latus et al. ( 6 ), who reported that residual outflow tract stenosis may counterbalance pulmonary regurgitation and prevent excessive right ventricular dilation, suggesting a complex interplay between pressure and volume load in tetralogy of Fallot. As suggested in previous studies, residual stenosis in the repaired tetralogy of Fallot may partially counterbalance pulmonary regurgitation and limit right ventricular dilatation ( 7 ). Our findings would indicate that the septal flattening observed in repaired tetralogy of Fallot patients is more than a morphological alteration and may also serve as a marker of underlying functional impairment. The correlation between septal-to-free wall curvature ratio and right-to-left ventricular end-diastolic and stroke volume ratios supports previous findings that septal geometry is sensitive to differentiate ventricular loading conditions. Critser et al. ( 19 ) demonstrated that cardiac MRI-derived septal curvature is significantly associated with clinical outcomes and pulmonary hypertension severity in neonates with bronchopulmonary dysplasia, with lower curvature values predicting need for therapy and respiratory support. In multivariate analysis, septal curvature outperformed other cardiac MRI parameters, demonstrating its diagnostic potential ( 19 ). Septal curvature not only reflects transseptal pressure gradient but also indicates ventricular volume imbalances. Zhan et al. ( 28 ) showed that in healthy neonates, the septal-to-free wall curvature ratio is highly correlated with transseptal pressure gradient and ventricular volume ratios during early circulatory adaptation, supporting the physiological mechanism for our observed associations in pathological findings ( 28 ). Septal flattening is accepted as an indicator of volume or pressure overload, with alterations in septal geometry affecting both left and right ventricular functions through ventricular interdependence mechanisms ( 8 ). Tetralogy of Fallot subgroups in our study, the curvature ratio also showed significant correlations with right ventricular volumes, ejection fraction, and right-to-left ventricular volume ratios. These results are consistent with the studies that have reported the impact of residual pulmonary regurgitation and right ventricular outflow tract stenosis on right ventricular remodeling after surgical repair ( 6 , 28 ). In our cohort, the lack of longitudinal follow-up and control data limits the potential to accurately determine the prognostic value of septal curvature. Additionally, due to the restrictions of clinical indications in current practice standards, invasive catheterization data were not available for our tetralogy of Fallot patients, which restricts direct hemodynamic correlation and comparison with catheter-based findings. Despite these limitations, ROC analysis confirmed the high discriminative power of the septal-to-free wall curvature ratio in identifying pulmonary hypertension and tetralogy of Fallot with stenosis, highlighting its potential role in diagnostic practice. In clinical practice, multiparametric evaluation including volumetric and functional measures, the severity of pulmonary regurgitation, and residual outflow tract stenosis ( 1 , 4 ). In follow-up tetralogy of Fallot patients, the integration of the septal-to-free wall curvature ratio into routine cardiac MRI imaging protocols may provide additive value in the non-invasive assessment of right ventricular pressure and volume loading, especially in patient populations where invasive assessment is not routinely feasible. The septal-to-free wall curvature ratio could also support decision-making regarding the timing of interventions and enhance risk stratification in complex congenital heart disease. This study has several limitations. The retrospective and single-center design may limit generalizability. Right heart catheterization data were unavailable for the tetralogy of Fallot groups, precluding direct comparison of the septal-to-free wall curvature ratio with invasive pressure measurements. On the other hand, simultaneous acquisition of MRI and hemodynamic data was not possible due to the lack of MRI-compatible pressure monitoring equipment. Additionally, although the septal-to-free wall curvature ratio was calculated using a standardized protocol, it involves manual tracing, which may introduce operator variability. While previous literature supports high interobserver agreement, our study did not perform an intra-class correlation coefficient analysis to confirm reproducibility. Future studies should consider automated post-processing techniques to minimize variability and enhance clinical applicability. Conclusions Cardiac MRI-derived septal-to-free wall curvature ratio effectively distinguishes between pressure and volume overload conditions and correlates with right ventricular remodeling across pulmonary hypertension and repaired tetralogy of Fallot in different loading pattern. Integration of the septal-to-free wall curvature ratio into cardiac MRI imaging protocol may enhance longitudinal monitoring, guide clinical decision-making, and facilitate early detection of adverse right ventricular remodeling. Declarations Competing Interests The authors have no relevant financial or non-financial interests to disclose. Funding None Author Contribution All authors contributed to the study's conception and design. Material preparation, data collection, and analysis were performed by SO, IKY. The first draft of the manuscript was written by IKY; all authors have study concepts/study design or data acquisition or data analysis/interpretation, manuscript drafting or manuscript revision for important intellectual content, approval of the final version of the submitted manuscript, and agreed to ensure any questions related to the work are appropriately resolved.The preliminary results of this research were presented as an oral presentation at the European Society for Pediatric Radiology (ESPR) 2025 Annual Meeting held in Romania. Acknowledgement Statements & DeclarationsAuthor contribution All authors contributed to the study's conception and design. Material preparation, data collection, and analysis were performed by SO, IKY, EO. The first draft of the manuscript was written by IKY; all authors have study concepts/study design or data acquisition or data analysis/interpretation, manuscript drafting or manuscript revision for important intellectual content, approval of the final version of the submitted manuscript, and agreed to ensure any questions related to the work are appropriately resolved.Funding None Data availability The data used to support the findings of this study are included in the article. The data of the study cohort is available upon request for some participating centers but not all due to relevant data protection laws. Ethics approval This study was performed in line with the principles of the Declaration of Helsinki. The ethics committee of Medipol University (Date, 30.05.2025/No. E-10840098-202.3.02-3438) approved this retrospective study, waiving individual consent.Conflicts of interest The authors have no relevant financial or non-financial interests to disclose. References Apostolopoulou SC, Manginas A, Kelekis NL, Noutsias M. Cardiovascular imaging approach in pre and postoperative tetralogy of Fallot. BMC Cardiovasc Disord. 2019;19:7. Hinton RB, Ware SM. Heart failure in pediatric patients with congenital heart disease. Circ Res. 2017;120(6):978–994. doi:10.1161/CIRCRESAHA.116.308996 Méndez C, Soler R, Rodriguez E, et al. Magnetic resonance imaging of abnormal ventricular septal motion in heart diseases: a pictorial review. Insights Imaging. 2011;2(4):483–492. doi:10.1007/s13244-011-0093-4 Geva T. Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support. J Cardiovasc Magn Reson. 2011;13(1):9. doi:10.1186/1532-429X-13-9 Geva T, Wald RM, Bucholz E, et al. Long-term management of right ventricular outflow tract dysfunction in repaired tetralogy of Fallot: a scientific statement from the American Heart Association. Circulation. 2024;150(25):e689–e707. doi:10.1161/CIR.0000000000001291 Latus H, Stammermann J, Voges I, et al. Impact of right ventricular pressure load after repair of tetralogy of Fallot. J Am Heart Assoc. 2022;11(7):e022694. doi:10.1161/JAHA.121.022694 Abd El Rahman MY, Hui W, Dsebissowa F, et al. Quantitative analysis of paradoxical interventricular septal motion following corrective surgery of tetralogy of Fallot. Pediatr Cardiol. 2005;26:379–384. Buckberg GD, RESTORE Group. The ventricular septum: the lion of right ventricular function, and its impact on right ventricular restoration. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S272–S278. Dong SJ, Crawley AP, MacGregor JH, et al. Regional left ventricular systolic function in relation to the cavity geometry in patients with chronic right ventricular pressure overload: a three-dimensional tagged magnetic resonance imaging study. Circulation. 1995;91:2359–2370. Beyar R, Dong SJ, Smith ER, et al. Ventricular interaction and septal deformation: a model compared with experimental data. Am J Physiol. 1993;265(6 Pt 2):H2044–H2056. Ricciardi MJ, Bossone E, Bach DS, et al. Echocardiographic predictors of an adverse response to a nifedipine trial in primary pulmonary hypertension: diminished left ventricular size and leftward ventricular septal bowing. Chest. 1999;116:1218–1223. King ME, Braun H, Goldblatt A, et al. Interventricular septal configuration as a predictor of right ventricular systolic hypertension in children: a cross-sectional echocardiographic study. Circulation. 1983;68:68–75. Roeleveld RJ, Marcus JT, Faes TJ, et al. Interventricular septal configuration at MR imaging and pulmonary arterial pressure in pulmonary hypertension. Radiology. 2005;234(3):710–717. doi:10.1148/radiol.2343040151 Swift AJ, Wild JM, Nagle SK, et al. Quantitative magnetic resonance imaging of pulmonary hypertension: a practical approach to the current state of the art. J Thorac Imaging. 2014;29(2):68–79. doi:10.1097/RTI.0000000000000079 He M, Jiang R, Fei-Sun, et al. Cardiac magnetic resonance imaging-derived septum swing index detects pulmonary hypertension: a diagnostic study. J Transl Int Med. 2023;11(4):459–467. doi:10.2478/jtim-2023-0114 Bouchard A, Higgins CB, Byrd BF 3rd, et al. Magnetic resonance imaging in pulmonary arterial hypertension. Am J Cardiol. 1985;56(15):938–942. Reisner SA, Azzam Z, Halmann M, et al. Septal/free wall curvature ratio: a noninvasive index of pulmonary arterial pressure. J Am Soc Echocardiogr. 1994;7:27–35. Pandya B, Moledina S, McKee A, et al. Analysis of the septal curvature with CMR in the paediatric population with pulmonary hypertension is a useful tool. J Cardiovasc Magn Reson. 2012;14(Suppl 1):P83. doi:10.1186/1532-429X-14-S1-P83 Critser J, et al. Cardiovascular magnetic resonance derived septal curvature in neonates with bronchopulmonary dysplasia-associated pulmonary hypertension. J Cardiovasc Magn Reson. 2020;22(1):50. Dellegrottaglie S, Sanz J, Poon M, et al. Pulmonary hypertension: accuracy of detection with left ventricular septal-to-free wall curvature ratio measured at cardiac MR. Radiology. 2007;243(1):63–69. Sciancalepore MA, Maffessanti F, Patel AR, et al. Three-dimensional analysis of interventricular septal curvature from cardiac magnetic resonance images for the evaluation of patients with pulmonary hypertension. Int J Cardiovasc Imaging. 2012;28(5):1073–1085. Vonk Noordegraaf A, Chin KM, Haddad F, et al. Pathophysiology of the right ventricle and of the pulmonary circulation in pulmonary hypertension: an update. Eur Respir J. 2019;53(1):1801900. doi:10.1183/13993003.01900-2018 Yock PG, Popp RL. Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation. Circulation. 1984;70:657–662. Simonneau G, Montani D, Celermajer DS, et al. Haemodynamic definitions and updated clinical classification of pulmonary hypertension. Eur Respir J. 2019;53(1):1801913. doi:10.1183/13993003.01913-2018 Rajiah P, Kanne JP. Cardiac MRI: part 1, cardiovascular shunts. AJR Am J Roentgenol. 2011;197(4):W603–W620. doi:10.2214/AJR.10.7257 Schulz-Menger J, Bluemke DA, Bremerich J, et al. Standardized image interpretation and post-processing in cardiovascular magnetic resonance: 2020 update. J Cardiovasc Magn Reson. 2020;22(1):19. doi:10.1186/s12968-020-00610-6 Ozkok S, Tosun O, Yucel IK, Celebi A. Cardiac MRI in surgically repaired tetralogy of Fallot: our initial experience. North Clin Istanb. 2022;9(6):622–631. doi:10.14744/nci.2021.43799 Zhan Y, et al. Changes in the interventricular septal curvature in healthy full-term neonates. J Ultrasound Med. 2020;39:1935–1944. Tables Table 1. Baseline Demographic and Cardiac MRI Parameters Among Study Groups Parameter Control (n=21) Left-to-Right Shunt with PHT (n=21) TOF with Stenosis (n=55) TOF without Stenosis (n=52) p-value BSA (m²) 1.72 ± 0.30 1.60 ± 0.58 1.73 ± 1.76 3.91 ± 18.28 0.783 Age (years) 13.50 ± 3.12 11.50 ± 5.55 13.14 ± 3.03 12.81 ± 4.37 0.673 RV-EDVI 90.67 ± 18.75 122.19 ± 65.43 156.35 ± 39.24 173.31 ± 41.74 <0.0001 RV-ESVI 46.92 ± 11.77 62.71 ± 44.96 89.85 ± 29.40 101.64 ± 30.67 <0.0001 RV-SVI 44.58 ± 9.58 59.67 ± 26.05 66.21 ± 17.29 71.33 ± 17.32 0.001 RV-EF (%) 48.33 ± 7.13 50.71 ± 9.34 43.23 ± 6.89 42.13 ± 6.88 0.011 LV-EDVI 89.79 ± 10.45 85.48 ± 44.37 88.50 ± 13.08 92.85 ± 19.76 0.001 LV-ESVI 41.21 ± 7.68 43.71 ± 33.16 45.62 ± 9.88 46.98 ± 12.95 0.175 LV-SVI 48.64 ± 7.09 43.24 ± 17.31 42.85 ± 6.71 45.93 ± 10.43 <0.0001 LV-EF (%) 54.21 ± 5.99 53.29 ± 12.04 48.71 ± 5.72 49.69 ± 6.52 0.233 Data are presented as mean ± standard deviation or median (interquartile range) as appropriate. p-values derived from one-way ANOVA or Kruskal–Wallis test as applicable. Abbreviations: BSA= Body Surface Area; LV-EDVI = Left Ventricular End-Diastolic Volume Index; LV-EF = Left Ventricular Ejection Fraction; LV-ESVI = Left Ventricular End-Systolic Volume Index; LV-SVI = Left Ventricular Stroke Volume Index; PHT = Pulmonary Hypertension; RV-EDVI = Right Ventricular End-Diastolic Volume Index; RV-EF = Right Ventricular Ejection Fraction; RV-ESVI = Right Ventricular End-Systolic Volume Index; RV-SVI = Right Ventricular Stroke Volume Index; TOF = Tetralogy of Fallot. Table 2 . Comparison of Septal-to-Free Wall Curvature and Right-to-Left Ventricular Volume Ratio Among Study Groups Parameter Control (n=21) Left-to-Right Shunt with PHT (n=21) TOF with Stenosis (n=55) TOF without Stenosis (n=52) p-value Septal-to-Free Wall Curvature Ratio 0.903 ± 0.054 0.610 ± 0.238 0.694 ± 0.175 0.742 ± 0.206 0.0003 Right-to-Left Ventricular EDV Ratio 0.907 ± 0.309 1.681 ± 0.923 1.780 ± 0.396 1.811 [1.531–1.990] 1.882 ± 0.316 <0.0001 Right-to-Left Ventricular SV Ratio 0.838 ± 0.288 1.508 ± 0.704 1.561 ± 0.369 1.543 1.589 ± 0.369 <0.0001 Data are presented as mean ± standard deviation or median (interquartile range) as appropriate. p-values derived from one-way ANOVA or Kruskal–Wallis test as applicable. Abbreviations: EDV = End-Diastolic Volume; PHT = Pulmonary Hypertension; SV = Right Ventricular Stroke Volume; TOF = Tetralogy of Fallot Table 3. Correlation between the septal-to-free wall curvature ratio and cardiac magnetic resonance imaging parameters between study cohorts Parameters Control (n=21) Left-to-Right Shunt with PHT (n=21) TOF with Stenosis (n=55) TOF without Stenosis (n=52) p-value r-value p-value r-value p-value r-value p-value r-value RV-EDVI 0.757 0.101 0.688 0.096 0.466 0.114 0.011* -0.353 RV-ESVI 0.768 0.095 0.364 0.214 0.476 0.098 0.001* -0.428 RV-SVI 0.818 0.074 0.570 -0.135 0.650 0.062 0.399 -0.119 RV-EF 0.766 0.096 0.063 -0.423 0.990 0.002 0.002* 0.413 LV-EDVI 0.305 0.295 0.963 0.011 0.895 -0.018 0.914 0.015 LV-ESVI 0.111 0.444 0.789 -0.064 0.844 0.027 0.790 -0.038 LV SVI 0.877 -0.045 0.990 -0.003 0.652 -0.062 0.571 0.081 LV-EF 0.155 -0.401 0.744 0.078 0.438 -0.107 0.680 0.059 Right-to-Left Ventricular EDV Ratio 0.327 0.295 0.769 -0.071 0.379 0.121 0.007* -0.367 Right-to-Left Ventricular SV Ratio 0.186 0.391 0.611 -0.121 0.454 0.103 0.342 -0.134 P-values indicate the significance level of differences across groups based on one-way ANOVA with Tukey post-hoc test. Abbreviations: BSA Body Surface Area; LV-EDVI = Left Ventricular End-Diastolic Volume Index; LV-EF = Left Ventricular Ejection Fraction; LV-ESVI = Left Ventricular End-Systolic Volume Index; LV-SVI = Left Ventricular Stroke Volume Index; PHT = Pulmonary Hypertension; RV-EDVI = Right Ventricular End-Diastolic Volume Index; RV-EF = Right Ventricular Ejection Fraction; RV-ESVI = Right Ventricular End-Systolic Volume Index; RV-SVI = Right Ventricular Stroke Volume Index; TOF = Tetralogy of Fallot. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7220176","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":496138625,"identity":"314fa3aa-ba4b-475a-926f-f1d07c7bff36","order_by":0,"name":"Ilker Kemal Yucel","email":"","orcid":"","institution":"Istanbul University Cerrahpaşa","correspondingAuthor":false,"prefix":"","firstName":"Ilker","middleName":"Kemal","lastName":"Yucel","suffix":""},{"id":496138626,"identity":"5eb0c379-5a20-4b9d-bff2-77361aaa674f","order_by":1,"name":"Kevser Banu Kose","email":"","orcid":"","institution":"Istanbul Medipol 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09:38:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7220176/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7220176/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88756092,"identity":"74c8651a-b006-47b8-8538-5cd25c0ef36c","added_by":"auto","created_at":"2025-08-11 07:15:17","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":74434,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurement of septal-to-free wall curvature ratio on end-systolic short-axis cardiac magnetic resonance images.16-year-old male patient with repaired tetralogy of Fallot, leftward displacement and flattening of the interventricular septum are observed at end-systole. Septal curvature was quantified by fitting an imaginary circle to the manually traced septal contour and calculating the inverse of the radius (C = 1/R), where the radius (R) was derived from the contour perimeter (C) using the formula R = C / 2π. The curvature ratio was computed by dividing the septal curvature (1/R_septum) by the free wall curvature (1/R_free wall), resulting in a dimensionless value. A curvature ratio close to 1 indicates a normal septal contour, while lower values signify progressive septal flattening and right ventricular pressure overload.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7220176/v1/08e96f245b0b2114850d8435.jpg"},{"id":88756769,"identity":"e8086204-e301-4a99-8586-a92d2d3edc1f","added_by":"auto","created_at":"2025-08-11 07:23:17","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":449742,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(a–c).\u003c/strong\u003eComparison of cardiac MRI-derived septal-to-free wall curvature ratio (a), \u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eRight-to-left ventricular end-diastolic \u003cem\u003evolume (b)\u003c/em\u003e, \u003cem\u003eand stroke volume ratio (c) \u003c/em\u003eacross study groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations: \u003c/strong\u003ePHT = Pulmonary Hypertension; TOF = Tetralogy of Fallot.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7220176/v1/c99078097b1ed5d9158aa92e.png"},{"id":88757903,"identity":"53975040-a451-409b-b3d0-f7bf509fafc5","added_by":"auto","created_at":"2025-08-11 07:31:17","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":726964,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003e(a-d).\u003c/strong\u003eCorrelation between septal-to-free wall curvature ratio and right ventricular end-diastolic volume index (a), end-systolic volume index (b), ejection fraction (c), and right-to-left ventricular end-diastolic volume ratio (d) in the Tetralogy of Fallot group.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations: \u003c/strong\u003eEDVI= end-diastolic volume index; ESVI= end-systolic volume index; EF= ejection fraction\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7220176/v1/8cceb3072c44a56013f47fc1.png"},{"id":88757904,"identity":"aa755da5-59b9-41a8-b67d-83482c2714b0","added_by":"auto","created_at":"2025-08-11 07:31:17","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":859013,"visible":true,"origin":"","legend":"\u003cp\u003eDiagnostic performance of cardiac MRI-derived right heart indices based on receiver operating characteristic curve analysis for Septal-to-free wall curvature ratio (a), Right-to-left ventricular end-diastolic volume ratio (b), and Right-to-left ventricular stroke volume ratio (c).\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7220176/v1/fed80c818776206be6ec7d34.png"},{"id":91041676,"identity":"a10f179d-e5a2-47f3-8ae4-fff805f97812","added_by":"auto","created_at":"2025-09-11 04:16:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3223734,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7220176/v1/a0b0cb7c-f1e1-42bc-b8e3-3ced7bda75ea.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"MRI-Based Septal Curvature Ratio for Differentiating Right Ventricular Pressure and Volume Overload in Repaired Tetralogy of Fallot and Shunt-Associated Pulmonary Hypertension","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eTetralogy of Fallot is the most common cyanotic congenital heart disease and usually undergoes early complete repair with ventricular septal defect closure and relief of right ventricular outflow tract obstruction (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). However, despite the success of this approach in improving long-term survival, it may lead to chronic complications, including residual right ventricular outflow tract obstruction and/or pulmonary regurgitation due to right ventricular outflow tract augmentation (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Right ventricular remodeling and dysfunction secondary to volume or pressure overload are frequently seen in several congenital heart diseases, either in tetralogy of Fallot and left-to-right shunt lesions (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn repaired tetralogy of Fallot, residual pulmonary regurgitation results in right ventricular dilatation, secondary tricuspid regurgitation, and progressive right ventricular volume overload (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). On the other hand, residual right ventricular outflow tract stenosis and associated pressure overload are accepted as independent predictors for adverse outcome (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Right ventricular volume/pressure overload significantly alters the shape and function of the interventricular septum and often causes interventricular septal flattening or leftward septal bowing (\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Earlier studies have shown that the end-systolic flattening of the interventricular septum primarily occurs because of right ventricular pressure overload (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Moreover, severe septal flattening is often considered to be associated with an unfavorable prognosis in pulmonary hypertension (\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eAlthough invasive hemodynamic assessment with cardiac catheterization remains the gold standard for diagnosis of pulmonary hypertension, cardiac magnetic resonance imaging (MRI)-derived parameters are widely used for non-invasive assessment of pulmonary hypertension (\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). The septal-to-free wall curvature ratio, derived by dividing the curvatures of the septum and the left ventricular free wall, has been defined as a quantitative marker of septal flattening, indicating a marker of systolic right ventricular hypertension or increased transseptal pressure differences (\u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). This ratio has demonstrated a strong correlation with invasive hemodynamic measurements and has shown high diagnostic accuracy in identifying pulmonary hypertension in both adult and pediatric cohorts (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan additionalcitationids=\"CR20\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). The use of cardiac MRI has expanded the ability to non-invasively quantify these morphological changes with high reproducibility and spatial resolution (\u003cspan additionalcitationids=\"CR18 CR19 CR20\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eHowever, the septal-to-free wall curvature ratio across different right ventricular loading patterns in congenital heart disease, such as repaired tetralogy of Fallot (with or without right ventricular outflow tract stenosis) and left-to-right shunt lesions, has not been evaluated before. This study aims to investigate the non-invasive differentiation of right ventricle remodeling across the septal-to-free wall curvature ratio between congenital heart disease subgroups in pediatric age and evaluate the relationship of septal-to-free wall curvature ratio with cardiac MRI parameters, including ventricular volume ratios.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003eThis retrospective study received ethical approval from the Institutional Review Board (Reference No: E-10840098-202.3.02-3438). All procedures were conducted following the ethical standards of the Declaration of Helsinki. Written informed consent for cardiac MRI was obtained from all participants, and parents or legal guardians for individuals under 18 years of age, before the examination.\u003c/p\u003e\u003cp\u003e\u003cb\u003eStudy Population\u003c/b\u003e\u003c/p\u003e\u003cp\u003e We retrospectively reviewed the clinical and imaging data of 256 patients who underwent cardiac MRI between 2020 and 2025. A total of 128 patients and 21 healthy controls were included in the study and categorized into four groups based on clinical and imaging characteristics.\u003c/p\u003e\u003cp\u003e\u003col\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eControl group (n\u0026thinsp;=\u0026thinsp;21)\u003c/b\u003e: Healthy individuals without congenital heart disease. No evidence of pulmonary hypertension and right ventricular outflow tract stenosis.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eTetralogy of Fallot without stenosis (n\u0026thinsp;=\u0026thinsp;52)\u003c/b\u003e: Patients with surgically repaired tetralogy of Fallot without residual left-to-right shunt and right ventricular outflow tract stenosis. These patients had moderate-to-severe pulmonary regurgitation measured by cardiac MRI.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eTetralogy of Fallot with stenosis (n\u0026thinsp;=\u0026thinsp;55)\u003c/b\u003e: Patients with surgically repaired tetralogy of Fallot with moderate-to-severe right ventricular outflow tract stenosis. These patients had moderate-to-severe pulmonary regurgitation measured by cardiac MRI.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003cspan\u003e\u003cli\u003e\u003cp\u003e\u003cb\u003eLeft-to-right shunt with pulmonary hypertension group (n\u0026thinsp;=\u0026thinsp;21)\u003c/b\u003e: Patients with significant left-to-right shunting lesions, including atrial septal defect (n\u0026thinsp;=\u0026thinsp;6), ventricular septal defect (n\u0026thinsp;=\u0026thinsp;7), partial anomalous pulmonary venous connection (n\u0026thinsp;=\u0026thinsp;6), and aortopulmonary window (n\u0026thinsp;=\u0026thinsp;2) with pulmonary hypertension. These patients had no evidence of right ventricular outflow tract stenosis.\u003c/p\u003e\u003c/li\u003e\u003c/span\u003e\u003c/ol\u003e\u003c/p\u003e\u003cp\u003eGroup classification for healthy control group patients with tetralogy of Fallot was based on noninvasive imaging modality and echocardiography-derived parameters, since right heart catheterization is not routinely performed for patients with Tetralogy of Fallot and is not indicated in the control group.\u003c/p\u003e\u003cp\u003eRight ventricular outflow tract stenosis is defined as increased right ventricular pressure in repaired tetralogy of Fallot patients. Right ventricular-pulmonary artery peak-to-peak systolic pressure higher than 40 mmHg is considered increased right ventricular systolic pressure (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eRight ventricular systolic pressure was estimated by continuous-wave Doppler echocardiography using the peak tricuspid regurgitant jet velocity, applying the modified Bernoulli equation.\u003c/p\u003e\u003cp\u003e\u003cb\u003eRight Ventricular Systolic Pressure\u0026thinsp;=\u0026thinsp;4 \u0026times; (peak tricuspid regurgitation velocity)\u0026sup2; + estimated right atrial pressure\u003c/b\u003e, with the right atrial pressure assumed to be 5 mmHg (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn patients with left-to-right shunt lesions and pulmonary hypertension, pulmonary artery pressure was retrospectively obtained from right heart catheterization records. Pulmonary hypertension was defined based on catheter-based diagnoses as mean pulmonary artery pressure\u0026thinsp;\u0026gt;\u0026thinsp;25 mmHg with pulmonary capillary wedge pressure\u0026thinsp;\u0026lt;\u0026thinsp;15 mmHg (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). Pulmonary-to-systemic flow ratio (Qp/Qs) was calculated using cardiac MRI phase-contrast imaging. A Qp/Qs ratio higher than 1.5 was considered indicative of a significant shunt (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eInclusion criteria for the patient cohort were: 1) patients with a left-to-right shunt who had right heart catheterization with a diagnosis of pulmonary hypertension confirmed by right heart catheterization; 2) individuals with previously repaired tetralogy of Fallot who were referred to our center for routine follow-up.\u003c/p\u003e\u003cp\u003ePatients were excluded if they had: 1) right heart catheterization or echocardiography performed more than three months before or after cardiac MRI; 2) left-sided cardiac disease or pulmonary disease; 3) cardiac MRI images of insufficient quality for analysis due to motion artifacts, poor breath-hold performance, and and arrhythmias; 4) patients with right ventricular outflow gradient gradient between 30\u0026ndash;40 mmHg were excluded to ensure distinct group separation.\u003c/p\u003e\u003cp\u003eDemographic information, including sex, age at the time of surgical repair, as well as age, weight, and height at the time of cardiac MRI, data of echocardiography, and right heart catheterization, were also obtained from the institutional electronic medical records.\u003c/p\u003e\u003cp\u003e\u003cb\u003eCardiac MRI Examination and Image Analysis\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAll Cardiac MRI examinations were performed using a 1.5 Tesla scanner (Avanto; Siemens Healthineers, Erlangen, Germany and 450W; Ingenia (Philips Healthcare, Best, the Netherlands) with a 32-channel phased-array abdominal coil with electrocardiographic gating.\u003c/p\u003e\u003cp\u003eThe imaging protocol included cine sequences for biventricular volumetric and functional analysis, as well as through-plane phase-contrast imaging for pulmonary artery flow quantification. Steady-state free precession cine images were acquired in contiguous short-axis slices covering the entire ventricles, along with standard long-axis views. Each set of images was acquired with retrospective gating. The scanning parameters for the Avanto (Siemens Healthineers, Erlangen, Germany) were as follows: repetition time\u0026thinsp;=\u0026thinsp;3.2 ms, echo time\u0026thinsp;=\u0026thinsp;1.6 ms, flip angle\u0026thinsp;=\u0026thinsp;60\u0026deg;, field of view\u0026thinsp;=\u0026thinsp;275 \u0026times; 340 mm, matrix size\u0026thinsp;=\u0026thinsp;224 \u0026times; 256, slice thickness\u0026thinsp;=\u0026thinsp;8 mm, slice gap\u0026thinsp;=\u0026thinsp;0 mm. The scanning parameters for the Ingenia (Philips Healthcare, Best, the Netherlands) were as follows: TR 3.6 ms; TE 1.5 ms; flip-angle 60\u0026deg;; bandwidth\u0026thinsp;\u0026plusmn;\u0026thinsp;90 kHz; matrix 192 \u0026times; 192; FOV 350 mm; NEX 1; slice thickness 8 mm; gap 0 mm.\u003c/p\u003e\u003cp\u003ePhase-contrast imaging was performed perpendicular to the main pulmonary artery just distal to the pulmonary valve. The optimal velocity encoding value of the pulmonary artery was calculated by the Bernoulli equation, reported gradients in the echocardiography report (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). The applied parameters for the phase contrast imaging sequence of the Avanto (Siemens Healthineers, Erlangen, Germany) were as follows: TR 31.8 ms; TE 2.9 ms; flip-angle 30\u0026deg;; bandwidth\u0026thinsp;\u0026plusmn;\u0026thinsp;60 kHz; matrix 192 \u0026times; 160; FOV 350 mm; NEX 1; slice thickness 6 mm. The scanning parameters for the Ingenia (Philips Healthcare, Best, the Netherlands) were as follows: TR 5 ms; TE 3 ms; flip-angle 20\u0026deg;; bandwidth\u0026thinsp;\u0026plusmn;\u0026thinsp;60 kHz; matrix 192 \u0026times; 160; FOV 350 mm; NEX 1; slice thickness 6 mm. The scanning parameters. All the examinations were acquired with retrospective electrocardiogram gating and 20\u0026ndash;25 reconstructed cardiac phases according to the heart rate.\u003c/p\u003e\u003cp\u003eAll cardiac MRI evaluations were performed using a software (IntelliSpace Portal 11.2, Philips Healthcare, Best, The Netherlands) by at least ten years of experience, blinded to patient information. Ventricular volume, function, pulmonary regurgitation, and Qp/Qs are calculated according to the recommendations (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). All measurement was performed automatically and manually corrected. Papillary muscles were included in the blood pool. Volumes were indexed to body surface area.\u003c/p\u003e\u003cp\u003eSeptal-to-free wall curvature ratio was measured on mid-ventricular short-axis cine images acquired using steady-state free precession sequences at end-systole. Measurements were performed using custom MATLAB scripts (MathWorks, Natick, MA, USA). Best-fit curves were applied to the manually traced contours of the interventricular septum and the corresponding free wall. The perimeter (C) of each contour was calculated. Assuming circular approximation, the radius of curvature (R) was then derived using the formula R\u0026thinsp;=\u0026thinsp;C/2π ( π\u0026thinsp;\u0026asymp;\u0026thinsp;3.1416). Septal curvature was expressed as the reciprocal of the radius (1/R) to obtain a dimensionless curvature value. The septal-to-free wall curvature ratio was computed by dividing the septal curvature (1/R septum) by the free wall curvature (1/R free wall). End-systole as the frame just before mitral valve opening. A rightward curvature was accepted as a positive value, and a value close to 0 indicated an almost flat; a negative value indicated a leftward curvature.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eSTATISTICAL ANALYSIS\u003c/h2\u003e\u003cp\u003eStatistical analyses were conducted using SPSS version 20.0 (IBM, Armonk, NY, USA). Descriptive statistics for continuous variables were presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation and median with interquartile range (IQR: 25th\u0026ndash;75th percentiles), where appropriate.\u003c/p\u003e\u003cp\u003eThe normality of data distribution was assessed using the Shapiro\u0026ndash;Wilk test. Depending on the distribution, either one-way analysis of variance [ANOVA] or Kruskal\u0026ndash;Wallis test methods were applied to compare differences among the four independent groups. For parameters with statistically significant overall differences (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), post hoc pairwise comparisons were performed using Tukey\u0026rsquo;s Honest Significant Difference test or Dunn\u0026rsquo;s test, respectively. Pearson or Spearman correlation coefficients were used to evaluate the relationships between septal curvature ratio and cardiac MRI parameters, based on data distribution.\u003c/p\u003e\u003cp\u003eReceiver operating characteristic (ROC) analyses were conducted for septal-to-free wall curvature ratio, right-to-left ventricular end-diastolic volume ratio, and right-to-left ventricular stroke volume ratio to assess their diagnostic performance in distinguishing each patient group from healthy controls. Area under the curve (AUC), optimal cut-off values, sensitivity, and specificity were reported. A P-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant for all tests.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 149 participants were included and classified into four groups: patients with pulmonary hypertension due to significant left-to-right shunt (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;21), postoperative patients without stenosis (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;52), with stenosis (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;55), and a healthy control group (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;21). No significant differences were found in age, body surface area (\u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.673 and \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0783, respectively).\u003c/p\u003e\u003cp\u003eAmong the patient population (\u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;128), the mean age was 12.85\u0026thinsp;\u0026plusmn;\u0026thinsp;3.92 years, and the median body surface area was 1.50 m\u0026sup2; [\u003cem\u003eIQR\u003c/em\u003e:1.30\u0026ndash;1.80]. The mean right ventricular end-diastolic volume index was 158.03\u0026thinsp;\u0026plusmn;\u0026thinsp;48.46 mL/m\u0026sup2;, with a median of 156.00 mL/m\u0026sup2;. The mean right ventricular ejection fraction was 43.98\u0026thinsp;\u0026plusmn;\u0026thinsp;7.88% and the left ventricular ejection fraction was 49.88\u0026thinsp;\u0026plusmn;\u0026thinsp;7.52%. The pulmonary regurgitation fraction was highest in postoperative patients with stenosis (38%\u0026plusmn;10%), followed by patients with significant left-to-right shunt (22\u0026thinsp;\u0026plusmn;\u0026thinsp;8%) and postoperative tetralogy of Fallot patients without stenosis (15\u0026thinsp;\u0026plusmn;\u0026thinsp;5%). No measurable regurgitation was observed in the control group. In patients with significant left-to-right shunting, the mean Qp/Qs ratio was 2.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5, indicating a substantial shunt, and the mean pulmonary artery pressure was 42\u0026thinsp;\u0026plusmn;\u0026thinsp;8 mmHg, reflecting mild-to-moderate pulmonary hypertension.\u003c/p\u003e\u003cp\u003eSignificant differences were observed across the four groups among right ventricular cardiac MRI parameters (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Left ventricular cardiac MRI parameters in terms of left ventricular end-diastolic and stroke volume index also demonstrated statistically significant differences (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.001, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001, respectively). Detailed distributions of the conventional cardiac MRI parameters among groups are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline Demographic and Cardiac MRI Parameters Among Study Groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl (n\u0026thinsp;=\u0026thinsp;21)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLeft-to-Right Shunt with PHT (n\u0026thinsp;=\u0026thinsp;21)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTOF with Stenosis (n\u0026thinsp;=\u0026thinsp;55)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTOF without Stenosis (n\u0026thinsp;=\u0026thinsp;52)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eBSA (m\u0026sup2;)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.73\u0026thinsp;\u0026plusmn;\u0026thinsp;1.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.91\u0026thinsp;\u0026plusmn;\u0026thinsp;18.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.783\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eAge (years)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13.50\u0026thinsp;\u0026plusmn;\u0026thinsp;3.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11.50\u0026thinsp;\u0026plusmn;\u0026thinsp;5.55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e13.14\u0026thinsp;\u0026plusmn;\u0026thinsp;3.03\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e12.81\u0026thinsp;\u0026plusmn;\u0026thinsp;4.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.673\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV-EDVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e90.67\u0026thinsp;\u0026plusmn;\u0026thinsp;18.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e122.19\u0026thinsp;\u0026plusmn;\u0026thinsp;65.43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e156.35\u0026thinsp;\u0026plusmn;\u0026thinsp;39.24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e173.31\u0026thinsp;\u0026plusmn;\u0026thinsp;41.74\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.0001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV-ESVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e46.92\u0026thinsp;\u0026plusmn;\u0026thinsp;11.77\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e62.71\u0026thinsp;\u0026plusmn;\u0026thinsp;44.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e89.85\u0026thinsp;\u0026plusmn;\u0026thinsp;29.40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e101.64\u0026thinsp;\u0026plusmn;\u0026thinsp;30.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.0001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV-SVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44.58\u0026thinsp;\u0026plusmn;\u0026thinsp;9.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e59.67\u0026thinsp;\u0026plusmn;\u0026thinsp;26.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e66.21\u0026thinsp;\u0026plusmn;\u0026thinsp;17.29\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e71.33\u0026thinsp;\u0026plusmn;\u0026thinsp;17.32\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV-EF (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e48.33\u0026thinsp;\u0026plusmn;\u0026thinsp;7.13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e50.71\u0026thinsp;\u0026plusmn;\u0026thinsp;9.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e43.23\u0026thinsp;\u0026plusmn;\u0026thinsp;6.89\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e42.13\u0026thinsp;\u0026plusmn;\u0026thinsp;6.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e0.011\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV-EDVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e89.79\u0026thinsp;\u0026plusmn;\u0026thinsp;10.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e85.48\u0026thinsp;\u0026plusmn;\u0026thinsp;44.37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e88.50\u0026thinsp;\u0026plusmn;\u0026thinsp;13.08\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e92.85\u0026thinsp;\u0026plusmn;\u0026thinsp;19.76\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e0.001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV-ESVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e41.21\u0026thinsp;\u0026plusmn;\u0026thinsp;7.68\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e43.71\u0026thinsp;\u0026plusmn;\u0026thinsp;33.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e45.62\u0026thinsp;\u0026plusmn;\u0026thinsp;9.88\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e46.98\u0026thinsp;\u0026plusmn;\u0026thinsp;12.95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.175\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV-SVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e48.64\u0026thinsp;\u0026plusmn;\u0026thinsp;7.09\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e43.24\u0026thinsp;\u0026plusmn;\u0026thinsp;17.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e42.85\u0026thinsp;\u0026plusmn;\u0026thinsp;6.71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e45.93\u0026thinsp;\u0026plusmn;\u0026thinsp;10.43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.0001\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV-EF (%)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54.21\u0026thinsp;\u0026plusmn;\u0026thinsp;5.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e53.29\u0026thinsp;\u0026plusmn;\u0026thinsp;12.04\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e48.71\u0026thinsp;\u0026plusmn;\u0026thinsp;5.72\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e49.69\u0026thinsp;\u0026plusmn;\u0026thinsp;6.52\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.233\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003eData are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or median (interquartile range) as appropriate. p-values derived from one-way ANOVA or Kruskal\u0026ndash;Wallis test as applicable.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eSignificant differences were found among the four groups regarding septal-to-free wall curvature (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0003), right-to-left ventricular end-diastolic volume (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), and right-to-left ventricular stroke volume (P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001) ratios. Detailed distributions of the cardiac MRI-derived parameter among groups are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of Septal-to-Free Wall Curvature and Right-to-Left Ventricular Volume Ratio Among Study Groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl (n\u0026thinsp;=\u0026thinsp;21)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLeft-to-Right Shunt with PHT (n\u0026thinsp;=\u0026thinsp;21)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTOF with Stenosis (n\u0026thinsp;=\u0026thinsp;55)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTOF without Stenosis (n\u0026thinsp;=\u0026thinsp;52)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSeptal-to-Free Wall Curvature Ratio\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.903\u0026thinsp;\u0026plusmn;\u0026thinsp;0.054\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.610\u0026thinsp;\u0026plusmn;\u0026thinsp;0.238\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.694\u0026thinsp;\u0026plusmn;\u0026thinsp;0.175\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.742\u0026thinsp;\u0026plusmn;\u0026thinsp;0.206\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.0003\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRight-to-Left Ventricular EDV Ratio\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.907\u0026thinsp;\u0026plusmn;\u0026thinsp;0.309\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.681\u0026thinsp;\u0026plusmn;\u0026thinsp;0.923\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.780\u0026thinsp;\u0026plusmn;\u0026thinsp;0.396 1.811 [1.531\u0026ndash;1.990]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.882\u0026thinsp;\u0026plusmn;\u0026thinsp;0.316\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRight-to-Left Ventricular\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eSV Ratio\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.838\u0026thinsp;\u0026plusmn;\u0026thinsp;0.288\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.508\u0026thinsp;\u0026plusmn;\u0026thinsp;0.704\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.561\u0026thinsp;\u0026plusmn;\u0026thinsp;0.369 1.543\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.589\u0026thinsp;\u0026plusmn;\u0026thinsp;0.369\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003eData are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation or median (interquartile range) as appropriate. p-values derived from one-way ANOVA or Kruskal\u0026ndash;Wallis test as applicable.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe septal-to-free wall curvature ratio was evaluated for its association with cardiac MRI measurements in each group. In patients with repaired tetralogy of Fallot, the septal-to-free wall curvature ratio demonstrated significant negative correlations with right ventricular end-diastolic volume (\u003cem\u003er\u003c/em\u003e= \u0026minus;\u0026thinsp;0.353, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0103), right ventricular end-systolic volume (r = \u0026minus;\u0026thinsp;0.428, p\u0026thinsp;=\u0026thinsp;0.0015), and the right-to-left ventricular end-diastolic volume ratio (\u003cem\u003er\u003c/em\u003e = \u0026minus;\u0026thinsp;0.367, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0075). A significant positive correlation was observed with right ventricular ejection fraction (\u003cem\u003er\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.413, p\u0026thinsp;=\u0026thinsp;0.0023) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Although a moderate negative correlation was observed between septal-to-free wall curvature ratio and right ventricular ejection fraction in the pulmonary hypertension with left-to-right shunt group (\u003cem\u003er\u003c/em\u003e = \u0026minus;\u0026thinsp;0.423), this did not reach statistical significance (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0635). No significant correlations were identified between septal curvature and cardiac parameters in the pulmonary stenosis group. Correlation between the septal-to-free wall curvature ratio and cardiac MRI parameters between study cohorts is presented in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eCorrelation between the septal-to-free wall curvature ratio and cardiac magnetic resonance imaging parameters between study cohorts\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"9\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eControl (n\u0026thinsp;=\u0026thinsp;21)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e\u003cp\u003eLeft-to-Right Shunt with PHT (n\u0026thinsp;=\u0026thinsp;21)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003eTOF with Stenosis (n\u0026thinsp;=\u0026thinsp;55)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e\u003cp\u003eTOF without Stenosis (n\u0026thinsp;=\u0026thinsp;52)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003er-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003er-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003er-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003er-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV-EDVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.757\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.101\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.688\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.096\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.466\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.114\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.011*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e-0.353\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV-ESVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.768\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.095\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.364\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.214\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.476\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.098\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.001*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e-0.428\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV-SVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.818\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.074\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.570\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.135\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.650\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.062\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.399\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e-0.119\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRV-EF\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.766\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.096\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.063\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.423\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.990\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.002\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.002*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.413\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV-EDVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.305\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.295\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.963\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.011\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.895\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e-0.018\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.914\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.015\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV-ESVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.111\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.444\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.789\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.064\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.844\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.027\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.790\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e-0.038\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV SVI\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.877\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e-0.045\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.990\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.003\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.652\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e-0.062\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.571\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.081\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLV-EF\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.155\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e-0.401\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.744\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.078\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.438\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e-0.107\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.680\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e0.059\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRight-to-Left Ventricular EDV Ratio\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.327\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.295\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.769\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.071\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.379\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.121\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.007*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e-0.367\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eRight-to-Left Ventricular SV Ratio\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.186\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.391\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.611\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e-0.121\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.454\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.103\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.342\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e\u003cp\u003e-0.134\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"9\"\u003eP-values indicate the significance level of differences across groups based on one-way ANOVA with Tukey post-hoc test.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eReceiver operating characteristic (ROC) analysis confirmed the diagnostic utility of the septal-to-free wall curvature ratio in distinguishing patient groups from healthy controls (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The septal-to-free wall curvature ratio showed high accuracy in the left-to-right shunt with pulmonary hypertension group (AUC\u0026thinsp;=\u0026thinsp;0.921; sensitivity\u0026thinsp;=\u0026thinsp;80.0%; specificity\u0026thinsp;=\u0026thinsp;95.2%) and tetralogy of Fallot without stenosis (AUC\u0026thinsp;=\u0026thinsp;0.877; sensitivity\u0026thinsp;=\u0026thinsp;73.1%; specificity\u0026thinsp;=\u0026thinsp;95.2%) and moderate performance in tetralogy of Fallot with stenosis (AUC\u0026thinsp;=\u0026thinsp;0.777; sensitivity\u0026thinsp;=\u0026thinsp;63.6%; specificity\u0026thinsp;=\u0026thinsp;100.0%). The right-to-left ventricular end-diastolic volume index ratio provided high accuracy in tetralogy of Fallot without stenosis (AUC\u0026thinsp;=\u0026thinsp;0.974; sensitivity\u0026thinsp;=\u0026thinsp;94.2%; specificity\u0026thinsp;=\u0026thinsp;100.0%), but performed less effectively in the pulmonary hypertension group (AUC\u0026thinsp;=\u0026thinsp;0.694; sensitivity\u0026thinsp;=\u0026thinsp;52.4%; specificity\u0026thinsp;=\u0026thinsp;100.0%). Similarly, the right-to-left ventricular stroke volume index ratio also demonstrated excellent diagnostic power, particularly in tetralogy of Fallot without stenosis (AUC\u0026thinsp;=\u0026thinsp;0.958; sensitivity\u0026thinsp;=\u0026thinsp;86.5%; specificity\u0026thinsp;=\u0026thinsp;100.0%) and was moderately effective in the pulmonary hypertension group (AUC\u0026thinsp;=\u0026thinsp;0.790; sensitivity\u0026thinsp;=\u0026thinsp;81.0%; specificity\u0026thinsp;=\u0026thinsp;83.3%).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study demonstrated that the septal-to-free wall curvature ratio is a quantitative non-invasive marker of interventricular septal flattening, which differs significantly between different right ventricular loading patterns. The septal-to-free wall curvature ratio value was significantly reduced in both pressure and volume overload conditions, with the lowest values observed in the left-to-right shunt with pulmonary hypertension group. These findings would support that septal deformation reflects distinct right ventricle loading patterns and may serve as a non-invasive indicator of the nature of the disease. Additionally, the septal-to-free wall curvature ratio showed significant correlations with right ventricular volume, ejection fraction, and right-to-left ventricular end-diastolic volume ratio.\u003c/p\u003e\u003cp\u003eCardiac MRI remains the gold standard for non-invasive, reproducible assessment of cardiac morphology and function, particularly for the right ventricle (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Among cardiac MRI-derived markers, the septal-to-free wall curvature ratio has been recognized as a reliable measurement of right ventricle pressure and volume overload (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan additionalcitationids=\"CR17 CR18 CR19 CR20\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). Previous studies have reported strong correlations between the septal-to-free wall curvature ratio and invasively measured pulmonary and right ventricle pressures (\u003cspan additionalcitationids=\"CR19\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Dellegrottaglie et al. (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e) demonstrated a significant correlation between curvature ratio and right ventricular systolic pressure measured by right heart catheterization, while Roeleveld et al. (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e) confirmed a linear relationship between systolic pulmonary arterial pressure and the degree of leftward septal bowing or flattening. Similarly, Pandya et al. (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e) demonstrated that the septal-to-free wall curvature ratio reflects a reliable non-invasive indicator of mean pulmonary artery pressure and pulmonary vascular resistance in children with pulmonary hypertension. Consistent with these studies, our findings revealed the septal-to-free wall curvature ratio as a sensitive marker of right-sided loading conditions. Importantly, while prior studies focused predominantly on isolated pulmonary hypertension (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan additionalcitationids=\"CR19\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e), our study is the first to compare the septal-to-free wall curvature ratio across different congenital heart disease subgroups in a pediatric population. Importantly, our study extends existing knowledge by systematically comparing septal-to-free wall curvature ratio across distinct congenital subgroups with varying degrees and types of right ventricle loading.\u003c/p\u003e\u003cp\u003eIn our study, the lowest value of septal-to-free wall curvature ratio were found in the left-to-right shunt-associated pulmonary hypertension group, which appears to reflect the combined effects of elevated pulmonary pressures, increased flow, and vascular remodeling. This group demonstrated both pressure and volume overload, leading to more pronounced septal distortion, likely due to increased right ventricle wall stress (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn contrast, repaired tetralogy of Fallot with residual stenosis group demonstrated more significant septal flattening compared to the non-stenotic tetralogy of Fallot, reflecting predominant right ventricular pressure overload. Despite a relatively preserved right ventricular ejection fraction, this group also had the markedly elevated pulmonary regurgitation fraction (38% \u0026plusmn; 10%), suggesting a dual burden of pressure and volume overload. These findings are consistent with those of Latus et al. (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e), who reported that residual outflow tract stenosis may counterbalance pulmonary regurgitation and prevent excessive right ventricular dilation, suggesting a complex interplay between pressure and volume load in tetralogy of Fallot. As suggested in previous studies, residual stenosis in the repaired tetralogy of Fallot may partially counterbalance pulmonary regurgitation and limit right ventricular dilatation (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Our findings would indicate that the septal flattening observed in repaired tetralogy of Fallot patients is more than a morphological alteration and may also serve as a marker of underlying functional impairment.\u003c/p\u003e\u003cp\u003eThe correlation between septal-to-free wall curvature ratio and right-to-left ventricular end-diastolic and stroke volume ratios supports previous findings that septal geometry is sensitive to differentiate ventricular loading conditions. Critser et al. (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e) demonstrated that cardiac MRI-derived septal curvature is significantly associated with clinical outcomes and pulmonary hypertension severity in neonates with bronchopulmonary dysplasia, with lower curvature values predicting need for therapy and respiratory support. In multivariate analysis, septal curvature outperformed other cardiac MRI parameters, demonstrating its diagnostic potential (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). Septal curvature not only reflects transseptal pressure gradient but also indicates ventricular volume imbalances. Zhan et al. (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e) showed that in healthy neonates, the septal-to-free wall curvature ratio is highly correlated with transseptal pressure gradient and ventricular volume ratios during early circulatory adaptation, supporting the physiological mechanism for our observed associations in pathological findings (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eSeptal flattening is accepted as an indicator of volume or pressure overload, with alterations in septal geometry affecting both left and right ventricular functions through ventricular interdependence mechanisms (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Tetralogy of Fallot subgroups in our study, the curvature ratio also showed significant correlations with right ventricular volumes, ejection fraction, and right-to-left ventricular volume ratios. These results are consistent with the studies that have reported the impact of residual pulmonary regurgitation and right ventricular outflow tract stenosis on right ventricular remodeling after surgical repair (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn our cohort, the lack of longitudinal follow-up and control data limits the potential to accurately determine the prognostic value of septal curvature. Additionally, due to the restrictions of clinical indications in current practice standards, invasive catheterization data were not available for our tetralogy of Fallot patients, which restricts direct hemodynamic correlation and comparison with catheter-based findings. Despite these limitations, ROC analysis confirmed the high discriminative power of the septal-to-free wall curvature ratio in identifying pulmonary hypertension and tetralogy of Fallot with stenosis, highlighting its potential role in diagnostic practice.\u003c/p\u003e\u003cp\u003eIn clinical practice, multiparametric evaluation including volumetric and functional measures, the severity of pulmonary regurgitation, and residual outflow tract stenosis (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). In follow-up tetralogy of Fallot patients, the integration of the septal-to-free wall curvature ratio into routine cardiac MRI imaging protocols may provide additive value in the non-invasive assessment of right ventricular pressure and volume loading, especially in patient populations where invasive assessment is not routinely feasible. The septal-to-free wall curvature ratio could also support decision-making regarding the timing of interventions and enhance risk stratification in complex congenital heart disease.\u003c/p\u003e\u003cp\u003eThis study has several limitations. The retrospective and single-center design may limit generalizability. Right heart catheterization data were unavailable for the tetralogy of Fallot groups, precluding direct comparison of the septal-to-free wall curvature ratio with invasive pressure measurements. On the other hand, simultaneous acquisition of MRI and hemodynamic data was not possible due to the lack of MRI-compatible pressure monitoring equipment. Additionally, although the septal-to-free wall curvature ratio was calculated using a standardized protocol, it involves manual tracing, which may introduce operator variability. While previous literature supports high interobserver agreement, our study did not perform an intra-class correlation coefficient analysis to confirm reproducibility. Future studies should consider automated post-processing techniques to minimize variability and enhance clinical applicability.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eCardiac MRI-derived septal-to-free wall curvature ratio effectively distinguishes between pressure and volume overload conditions and correlates with right ventricular remodeling across pulmonary hypertension and repaired tetralogy of Fallot in different loading pattern. Integration of the septal-to-free wall curvature ratio into cardiac MRI imaging protocol may enhance longitudinal monitoring, guide clinical decision-making, and facilitate early detection of adverse right ventricular remodeling.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eCompeting Interests\u003c/h2\u003e\n\u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003eAll authors contributed to the study\u0026apos;s conception and design. Material preparation, data collection, and analysis were performed by SO, IKY. The first draft of the manuscript was written by IKY; all authors have study concepts/study design or data acquisition or data analysis/interpretation, manuscript drafting or manuscript revision for important intellectual content, approval of the final version of the submitted manuscript, and agreed to ensure any questions related to the work are appropriately resolved.The preliminary results of this research were presented as an oral presentation at the European Society for Pediatric Radiology (ESPR) 2025 Annual Meeting held in Romania.\u003c/p\u003e\n\u003ch2\u003eAcknowledgement\u003c/h2\u003e\n\u003cp\u003eStatements \u0026amp; DeclarationsAuthor contribution All authors contributed to the study\u0026apos;s conception and design. Material preparation, data collection, and analysis were performed by SO, IKY, EO. The first draft of the manuscript was written by IKY; all authors have study concepts/study design or data acquisition or data analysis/interpretation, manuscript drafting or manuscript revision for important intellectual content, approval of the final version of the submitted manuscript, and agreed to ensure any questions related to the work are appropriately resolved.Funding None Data availability The data used to support the findings of this study are included in the article. The data of the study cohort is available upon request for some participating centers but not all due to relevant data protection laws. Ethics approval This study was performed in line with the principles of the Declaration of Helsinki. The ethics committee of Medipol University (Date, 30.05.2025/No. E-10840098-202.3.02-3438) approved this retrospective study, waiving individual consent.Conflicts of interest The authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eApostolopoulou SC, Manginas A, Kelekis NL, Noutsias M. Cardiovascular imaging approach in pre and postoperative tetralogy of Fallot. BMC Cardiovasc Disord. 2019;19:7.\u003c/li\u003e\n \u003cli\u003eHinton RB, Ware SM. Heart failure in pediatric patients with congenital heart disease. Circ Res. 2017;120(6):978\u0026ndash;994. doi:10.1161/CIRCRESAHA.116.308996\u003c/li\u003e\n \u003cli\u003eM\u0026eacute;ndez C, Soler R, Rodriguez E, et al. Magnetic resonance imaging of abnormal ventricular septal motion in heart diseases: a pictorial review. Insights Imaging. 2011;2(4):483\u0026ndash;492. doi:10.1007/s13244-011-0093-4\u003c/li\u003e\n \u003cli\u003eGeva T. Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support. J Cardiovasc Magn Reson. 2011;13(1):9. doi:10.1186/1532-429X-13-9\u003c/li\u003e\n \u003cli\u003eGeva T, Wald RM, Bucholz E, et al. Long-term management of right ventricular outflow tract dysfunction in repaired tetralogy of Fallot: a scientific statement from the American Heart Association. Circulation. 2024;150(25):e689\u0026ndash;e707. doi:10.1161/CIR.0000000000001291\u003c/li\u003e\n \u003cli\u003eLatus H, Stammermann J, Voges I, et al. Impact of right ventricular pressure load after repair of tetralogy of Fallot. J Am Heart Assoc. 2022;11(7):e022694. doi:10.1161/JAHA.121.022694\u003c/li\u003e\n \u003cli\u003eAbd El Rahman MY, Hui W, Dsebissowa F, et al. Quantitative analysis of paradoxical interventricular septal motion following corrective surgery of tetralogy of Fallot. Pediatr Cardiol. 2005;26:379\u0026ndash;384.\u003c/li\u003e\n \u003cli\u003eBuckberg GD, RESTORE Group. The ventricular septum: the lion of right ventricular function, and its impact on right ventricular restoration. Eur J Cardiothorac Surg. 2006;29(Suppl 1):S272\u0026ndash;S278.\u003c/li\u003e\n \u003cli\u003eDong SJ, Crawley AP, MacGregor JH, et al. Regional left ventricular systolic function in relation to the cavity geometry in patients with chronic right ventricular pressure overload: a three-dimensional tagged magnetic resonance imaging study. Circulation. 1995;91:2359\u0026ndash;2370.\u003c/li\u003e\n \u003cli\u003eBeyar R, Dong SJ, Smith ER, et al. Ventricular interaction and septal deformation: a model compared with experimental data. Am J Physiol. 1993;265(6 Pt 2):H2044\u0026ndash;H2056.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eRicciardi MJ, Bossone E, Bach DS, et al. Echocardiographic predictors of an adverse response to a nifedipine trial in primary pulmonary hypertension: diminished left ventricular size and leftward ventricular septal bowing. Chest. 1999;116:1218\u0026ndash;1223.\u003c/li\u003e\n \u003cli\u003eKing ME, Braun H, Goldblatt A, et al. Interventricular septal configuration as a predictor of right ventricular systolic hypertension in children: a cross-sectional echocardiographic study. Circulation. 1983;68:68\u0026ndash;75.\u003c/li\u003e\n \u003cli\u003eRoeleveld RJ, Marcus JT, Faes TJ, et al. Interventricular septal configuration at MR imaging and pulmonary arterial pressure in pulmonary hypertension. Radiology. 2005;234(3):710\u0026ndash;717. doi:10.1148/radiol.2343040151\u003c/li\u003e\n \u003cli\u003eSwift AJ, Wild JM, Nagle SK, et al. Quantitative magnetic resonance imaging of pulmonary hypertension: a practical approach to the current state of the art. J Thorac Imaging. 2014;29(2):68\u0026ndash;79. doi:10.1097/RTI.0000000000000079\u003c/li\u003e\n \u003cli\u003eHe M, Jiang R, Fei-Sun, et al. Cardiac magnetic resonance imaging-derived septum swing index detects pulmonary hypertension: a diagnostic study. J Transl Int Med. 2023;11(4):459\u0026ndash;467. doi:10.2478/jtim-2023-0114\u003c/li\u003e\n \u003cli\u003eBouchard A, Higgins CB, Byrd BF 3rd, et al. Magnetic resonance imaging in pulmonary arterial hypertension. Am J Cardiol. 1985;56(15):938\u0026ndash;942.\u003c/li\u003e\n \u003cli\u003eReisner SA, Azzam Z, Halmann M, et al. Septal/free wall curvature ratio: a noninvasive index of pulmonary arterial pressure. J Am Soc Echocardiogr. 1994;7:27\u0026ndash;35.\u003c/li\u003e\n \u003cli\u003ePandya B, Moledina S, McKee A, et al. Analysis of the septal curvature with CMR in the paediatric population with pulmonary hypertension is a useful tool. J Cardiovasc Magn Reson. 2012;14(Suppl 1):P83. doi:10.1186/1532-429X-14-S1-P83\u003c/li\u003e\n \u003cli\u003eCritser J, et al. Cardiovascular magnetic resonance derived septal curvature in neonates with bronchopulmonary dysplasia-associated pulmonary hypertension. J Cardiovasc Magn Reson. 2020;22(1):50.\u003c/li\u003e\n \u003cli\u003eDellegrottaglie S, Sanz J, Poon M, et al. Pulmonary hypertension: accuracy of detection with left ventricular septal-to-free wall curvature ratio measured at cardiac MR. Radiology. 2007;243(1):63\u0026ndash;69.\u003c/li\u003e\n \u003cli\u003eSciancalepore MA, Maffessanti F, Patel AR, et al. Three-dimensional analysis of interventricular septal curvature from cardiac magnetic resonance images for the evaluation of patients with pulmonary hypertension. Int J Cardiovasc Imaging. 2012;28(5):1073\u0026ndash;1085.\u003c/li\u003e\n \u003cli\u003eVonk Noordegraaf A, Chin KM, Haddad F, et al. Pathophysiology of the right ventricle and of the pulmonary circulation in pulmonary hypertension: an update. Eur Respir J. 2019;53(1):1801900. doi:10.1183/13993003.01900-2018\u003c/li\u003e\n \u003cli\u003eYock PG, Popp RL. Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation. Circulation. 1984;70:657\u0026ndash;662.\u003c/li\u003e\n \u003cli\u003eSimonneau G, Montani D, Celermajer DS, et al. Haemodynamic definitions and updated clinical classification of pulmonary hypertension. Eur Respir J. 2019;53(1):1801913. doi:10.1183/13993003.01913-2018\u003c/li\u003e\n \u003cli\u003eRajiah P, Kanne JP. Cardiac MRI: part 1, cardiovascular shunts. AJR Am J Roentgenol. 2011;197(4):W603\u0026ndash;W620. doi:10.2214/AJR.10.7257\u003c/li\u003e\n \u003cli\u003eSchulz-Menger J, Bluemke DA, Bremerich J, et al. Standardized image interpretation and post-processing in cardiovascular magnetic resonance: 2020 update. J Cardiovasc Magn Reson. 2020;22(1):19. doi:10.1186/s12968-020-00610-6\u003c/li\u003e\n \u003cli\u003eOzkok S, Tosun O, Yucel IK, Celebi A. Cardiac MRI in surgically repaired tetralogy of Fallot: our initial experience. North Clin Istanb. 2022;9(6):622\u0026ndash;631. doi:10.14744/nci.2021.43799\u003c/li\u003e\n \u003cli\u003eZhan Y, et al. Changes in the interventricular septal curvature in healthy full-term neonates. J Ultrasound Med. 2020;39:1935\u0026ndash;1944.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e \u003cem\u003eBaseline Demographic and Cardiac MRI Parameters Among Study Groups\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" align=\"\" width=\"671\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eControl (n=21)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLeft-to-Right Shunt with PHT (n=21)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTOF with Stenosis (n=55)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTOF without Stenosis (n=52)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eBSA (m\u0026sup2;)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e1.72 \u0026plusmn; 0.30\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e1.60 \u0026plusmn; 0.58\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e1.73 \u0026plusmn; 1.76\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e3.91 \u0026plusmn; 18.28\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e0.783\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge (years)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e13.50 \u0026plusmn; 3.12\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e11.50 \u0026plusmn; 5.55\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e13.14 \u0026plusmn; 3.03\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e12.81 \u0026plusmn; 4.37\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e0.673\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRV-EDVI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e90.67 \u0026plusmn; 18.75\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e122.19 \u0026plusmn; 65.43\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e156.35 \u0026plusmn; 39.24\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e173.31 \u0026plusmn; 41.74\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.0001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRV-ESVI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e46.92 \u0026plusmn; 11.77\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e62.71 \u0026plusmn; 44.96\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e89.85 \u0026plusmn; 29.40\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e101.64 \u0026plusmn; 30.67\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.0001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRV-SVI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e44.58 \u0026plusmn; 9.58\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e59.67 \u0026plusmn; 26.05\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e66.21 \u0026plusmn; 17.29\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e71.33 \u0026plusmn; 17.32\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRV-EF (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e48.33 \u0026plusmn; 7.13\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e50.71 \u0026plusmn; 9.34\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e43.23 \u0026plusmn; 6.89\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e42.13 \u0026plusmn; 6.88\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.011\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLV-EDVI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e89.79 \u0026plusmn; 10.45\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e85.48 \u0026plusmn; 44.37\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e88.50 \u0026plusmn; 13.08\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e92.85 \u0026plusmn; 19.76\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLV-ESVI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e41.21 \u0026plusmn; 7.68\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e43.71 \u0026plusmn; 33.16\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e45.62 \u0026plusmn; 9.88\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e46.98 \u0026plusmn; 12.95\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e0.175\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLV-SVI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e48.64 \u0026plusmn; 7.09\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e43.24 \u0026plusmn; 17.31\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e42.85 \u0026plusmn; 6.71\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e45.93 \u0026plusmn; 10.43\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.0001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 15.4993%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLV-EF (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.1386%;\"\u003e\n \u003cp\u003e54.21 \u0026plusmn; 5.99\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.076%;\"\u003e\n \u003cp\u003e53.29 \u0026plusmn; 12.04\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.8838%;\"\u003e\n \u003cp\u003e48.71 \u0026plusmn; 5.72\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19.225%;\"\u003e\n \u003cp\u003e49.69 \u0026plusmn; 6.52\u003cbr\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11.1773%;\"\u003e\n \u003cp\u003e0.233\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cem\u003eData are presented as mean \u0026plusmn; standard deviation or median (interquartile range) as appropriate. p-values derived from one-way ANOVA or Kruskal\u0026ndash;Wallis test as applicable.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e BSA= Body Surface Area; LV-EDVI = Left Ventricular End-Diastolic Volume Index; LV-EF = Left Ventricular Ejection Fraction; LV-ESVI = Left Ventricular End-Systolic Volume Index; LV-SVI = Left Ventricular Stroke Volume Index; PHT = Pulmonary Hypertension; RV-EDVI = Right Ventricular End-Diastolic Volume Index; RV-EF = Right Ventricular Ejection Fraction; RV-ESVI = Right Ventricular End-Systolic Volume Index; RV-SVI = Right Ventricular Stroke Volume Index; TOF = Tetralogy of Fallot.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e. Comparison of Septal-to-Free Wall Curvature and Right-to-Left Ventricular Volume Ratio Among Study Groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"643\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.5607%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.0436%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eControl (n=21)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.405%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLeft-to-Right Shunt with PHT (n=21)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.5109%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTOF with Stenosis (n=55)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.1994%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTOF without Stenosis (n=52)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.2804%;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.5607%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSeptal-to-Free Wall Curvature Ratio\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.0436%;\"\u003e\n \u003cp\u003e0.903 \u0026plusmn; 0.054\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.405%;\"\u003e\n \u003cp\u003e0.610 \u0026plusmn; 0.238\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.5109%;\"\u003e\n \u003cp\u003e0.694 \u0026plusmn; 0.175\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.1994%;\"\u003e\n \u003cp\u003e0.742 \u0026plusmn; 0.206\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.2804%;\"\u003e\n \u003cp\u003e0.0003\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.5607%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight-to-Left Ventricular\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eEDV Ratio\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.0436%;\"\u003e\n \u003cp\u003e0.907 \u0026plusmn; 0.309\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.405%;\"\u003e\n \u003cp\u003e1.681 \u0026plusmn; 0.923\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.5109%;\"\u003e\n \u003cp\u003e1.780 \u0026plusmn; 0.396 1.811 [1.531\u0026ndash;1.990]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.1994%;\"\u003e\n \u003cp\u003e1.882 \u0026plusmn; 0.316\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.2804%;\"\u003e\n \u003cp\u003e\u0026lt;0.0001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20.5607%;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight-to-Left Ventricular\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eSV Ratio\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.0436%;\"\u003e\n \u003cp\u003e0.838 \u0026plusmn; 0.288\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.405%;\"\u003e\n \u003cp\u003e1.508 \u0026plusmn; 0.704\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.5109%;\"\u003e\n \u003cp\u003e1.561 \u0026plusmn; 0.369 1.543\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 16.1994%;\"\u003e\n \u003cp\u003e1.589 \u0026plusmn; 0.369\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.2804%;\"\u003e\n \u003cp\u003e\u0026lt;0.0001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cem\u003eData are presented as mean \u0026plusmn; standard deviation or median (interquartile range) as appropriate. p-values derived from one-way ANOVA or Kruskal\u0026ndash;Wallis test as applicable.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e EDV = End-Diastolic Volume; PHT = Pulmonary Hypertension; SV = Right Ventricular Stroke Volume; TOF = Tetralogy of Fallot\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3.\u003c/strong\u003e \u003cem\u003eCorrelation between the\u0026nbsp;\u003c/em\u003eseptal-to-free wall curvature ratio\u003cem\u003e\u0026nbsp;\u003cem\u003eand cardiac magnetic resonance imaging parameters between study cohorts\u003c/em\u003e\u003c/em\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"699\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eParameters\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 136px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eControl (n=21)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 134px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLeft-to-Right Shunt with PHT (n=21)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTOF with Stenosis (n=55)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 131px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTOF without Stenosis (n=52)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e\u003cstrong\u003er-value\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003er-value\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e\u003cstrong\u003er-value\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e\u003cstrong\u003er-value\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRV-EDVI\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.757\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.101\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.688\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.096\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.466\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.114\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.011*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.353\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRV-ESVI\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.768\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.095\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.364\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.214\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.476\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.098\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.001*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.428\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRV-SVI\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.818\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.074\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.570\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.135\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.650\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.062\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.399\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.119\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRV-EF\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.766\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.096\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.063\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.423\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.002\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.002*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.413\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLV-EDVI\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.305\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.295\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.963\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.895\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e-0.018\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.914\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.015\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLV-ESVI\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.111\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.444\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.789\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.064\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.844\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.027\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.790\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.038\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLV SVI\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.877\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e-0.045\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.990\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.652\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e-0.062\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.571\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.081\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLV-EF\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.155\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e-0.401\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.744\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.078\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.438\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e-0.107\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.680\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.059\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight-to-Left Ventricular\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eEDV Ratio\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.327\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.295\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.769\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.071\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.379\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.121\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.007*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.367\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRight-to-Left Ventricular\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eSV Ratio\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003e0.186\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.391\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 68px;\"\u003e\n \u003cp\u003e0.611\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.121\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e0.454\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 67px;\"\u003e\n \u003cp\u003e0.103\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e0.342\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 66px;\"\u003e\n \u003cp\u003e-0.134\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eP-values indicate the significance level of differences across groups based on one-way ANOVA with Tukey post-hoc test.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e BSA Body Surface Area; LV-EDVI = Left Ventricular End-Diastolic Volume Index; LV-EF = Left Ventricular Ejection Fraction; LV-ESVI = Left Ventricular End-Systolic Volume Index; LV-SVI = Left Ventricular Stroke Volume Index; PHT = Pulmonary Hypertension; RV-EDVI = Right Ventricular End-Diastolic Volume Index; RV-EF = Right Ventricular Ejection Fraction; RV-ESVI = Right Ventricular End-Systolic Volume Index; RV-SVI = Right Ventricular Stroke Volume Index; TOF = Tetralogy of Fallot.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Pediatric, Tetralogy of Fallot, Pulmonary Hypertension, Septal-to-Free Wall Curvature Ratio, Cardiac Magnetic Resonance Imaging (MRI)","lastPublishedDoi":"10.21203/rs.3.rs-7220176/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7220176/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCardiac MRI-derived septal-to-free wall curvature ratio is a non-invasive marker to evaluate right ventricular pressure and pulmonary hypertension.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjective:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo investigate whether the septal-to-free wall curvature ratio measured by cardiac MRI can differentiate between right ventricle pressure and volume overload in different right ventricle overload conditions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBetween 2020 and 2025, 149 participants were classified into four groups: controls (\u003cem\u003en\u003c/em\u003e=21), patients repaired with (\u003cem\u003en\u003c/em\u003e=55) and without (\u003cem\u003en\u003c/em\u003e=52) right ventricular outflow tract stenosis, and patients with left-to-right shunt and pulmonary hypertension (\u003cem\u003en\u003c/em\u003e=21), retrospectively. The association of the septal-to-free wall curvature ratio, calculated using MATLAB, with functional parameters and group differences was analyzed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSignificant differences in septal-to-free wall curvature and right-to-left ventricular volume ratios were found across groups (P\u0026lt;0.05). The curvature ratio was lowest in the left-to-right shunt lesions with pulmonary hypertension (0.610 ± 0.238), followed by the tetralogy of Fallot with stenosis group (0.670 ± 0.238). The curvature ratio showed moderate-to-strong correlations with right-to-left ventricular end-diastolic (r = –0.59) and stroke volume ratios (r = –0.54). ROC analysis showed excellent diagnostic performance in detecting pulmonary hypertension (AUC=0.921) and strong discriminatory ability in tetralogy of Fallot without stenosis (AUC=0.877), while moderate performance was observed in tetralogy of Fallot with stenosis (AUC=0.777). Significant negative correlations were identified between curvature ratio and right ventricle volumes and right-to-left ventricle ratios, while a positive correlation was found with right ventricle ejection fraction in the tetralogy of Fallot subgroup.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCardiac MRI-derived septal-to-free wall curvature and volume ratios offer valuable non-invasive markers for distinguishing right ventricular pressure and volume overload.\u003c/p\u003e","manuscriptTitle":"MRI-Based Septal Curvature Ratio for Differentiating Right Ventricular Pressure and Volume Overload in Repaired Tetralogy of Fallot and Shunt-Associated Pulmonary Hypertension","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-11 07:15:12","doi":"10.21203/rs.3.rs-7220176/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0b296e06-58ed-414c-ab06-c6c0d87aa38c","owner":[],"postedDate":"August 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-11T04:08:24+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-11 07:15:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7220176","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7220176","identity":"rs-7220176","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}