MRI Features and Diagnostic Value of Diffusion-Weighted Imaging in Pediatric Ovarian Tumors: A Multicenter Retrospective Study

MRI Features and Diagnostic Value of Diffusion-Weighted Imaging in Pediatric Ovarian Tumors: A Multicenter Retrospective Study | 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 Features and Diagnostic Value of Diffusion-Weighted Imaging in Pediatric Ovarian Tumors: A Multicenter Retrospective Study Gulnora Yusupaliyeva, Umida Umarova, Mukhayo Khayitboeva, Laylo Sultanova, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8727001/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 26 Mar, 2026 Read the published version in BMC Pediatrics → Version 1 posted 16 You are reading this latest preprint version Abstract Background Ovarian tumors in children and adolescents represent a diagnostically challenging and heterogeneous group of diseases. Accurate preoperative differentiation between benign and malignant lesions is essential for optimal treatment planning and preservation of reproductive potential. Magnetic resonance imaging (MRI) plays a key role in the evaluation of indeterminate adnexal masses; however, conventional morphological MRI features often overlap between benign and malignant tumors. Diffusion-weighted imaging (DWI) may provide additional diagnostic information by reflecting tumor cellularity. Methods This multicenter retrospective observational study included pediatric patients with suspected ovarian tumors examined at two tertiary referral centers between 2020 and 2025. A total of 152 patients were evaluated, of whom 96 underwent pelvic MRI. Histopathological confirmation of diagnosis was available for all patients, while diffusion-weighted imaging with apparent diffusion coefficient (ADC) mapping was performed in 32 cases. MRI assessment included analysis of tumor morphology, presence of solid components, contour characteristics, extracapsular extension, ascites, lymphadenopathy, and peritoneal deposits. Diagnostic performance of MRI and DWI was assessed using receiver operating characteristic (ROC) analysis. Results Several morphological MRI features, including solid components, irregular margins, extracapsular growth, ascites, lymphadenopathy, and peritoneal deposits, were significantly more frequent in malignant tumors (p < 0.001). Tumor size and cystic–solid architecture alone were not reliable indicators of malignancy. ADC values of the solid tumor component were significantly lower in malignant compared with benign lesions (0.8 ± 0.09 ×10⁻³ mm²/s vs. 1.2 ± 0.13 ×10⁻³ mm²/s, p = 0.019). ROC analysis demonstrated high diagnostic accuracy of MRI based on morphological features (AUC = 0.94). The combined use of morphological MRI and DWI improved diagnostic performance, with a sensitivity of 91.0%, specificity of 88.0%, and overall accuracy of 89.0%. Conclusions MRI is a highly informative modality for the evaluation of ovarian tumors in children and adolescents; however, conventional morphological criteria alone may be insufficient, particularly in early-stage malignant epithelial tumors. Diffusion-weighted imaging with quantitative ADC assessment provides significant additional diagnostic value and improves differentiation between benign and malignant ovarian tumors. A comprehensive MRI approach incorporating both morphological and functional parameters may enhance diagnostic confidence and support optimal clinical decision-making in pediatric patients. Pediatric ovarian tumors Magnetic resonance imaging Diffusion-weighted imaging Apparent diffusion coefficient Benign and malignant tumors Diagnostic accuracy Introduction Ovarian tumors in children and adolescents represent a rare but clinically significant group of diseases characterized by marked histological heterogeneity and variable biological behavior [ 1 , 2 ]. Although ovarian neoplasms account for a small proportion of pediatric tumors, their timely and accurate diagnosis is essential, as delayed or incorrect assessment may lead to suboptimal treatment strategies, unnecessary radical surgery, and potential loss of reproductive function [ 3 ]. In pediatric patients, preservation of ovarian tissue and fertility remains a critical consideration alongside oncological safety [ 4 ]. Ultrasound is widely used as the first-line imaging modality for the evaluation of adnexal masses in children due to its availability, absence of ionizing radiation, and high sensitivity in detecting ovarian lesions [ 5 ]. However, ultrasound findings are often nonspecific, particularly in cases of large, complex, or atypically located tumors. As a result, diagnostic uncertainty frequently persists, necessitating further imaging evaluation [ 6 ]. Magnetic resonance imaging (MRI) plays a pivotal role in the assessment of indeterminate ovarian masses in pediatric patients. Owing to its excellent soft-tissue contrast, multiplanar imaging capability, and lack of ionizing radiation, MRI is considered the most informative cross-sectional imaging technique for pelvic evaluation in children and adolescents [ 7 , 8 ]. Conventional MRI allows detailed assessment of tumor morphology, internal architecture, signal characteristics, and extent of disease, which are essential for preoperative planning [ 9 ]. Despite these advantages, differentiation between benign and malignant ovarian tumors based solely on conventional morphological MRI features remains challenging in pediatric practice [ 10 ]. Several imaging characteristics traditionally associated with malignancy—such as the presence of solid components, heterogeneous signal intensity, irregular margins, and complex cystic–solid architecture—may also be observed in benign lesions, including mature teratomas and certain epithelial tumors [ 11 , 12 ]. This overlap of imaging features significantly limits the specificity of standard morphological MRI assessment and may result in diagnostic ambiguity [ 13 ]. Advanced MRI techniques, particularly diffusion-weighted imaging (DWI), have emerged as promising tools for improving diagnostic accuracy in oncologic imaging [ 14 ]. DWI provides functional information related to tissue cellularity and microstructural organization by evaluating the diffusion of water molecules within tissues. Quantitative analysis using apparent diffusion coefficient (ADC) values allows objective assessment of diffusion restriction, which is typically more pronounced in highly cellular malignant tumors [ 15 , 16 ]. In adult populations, the diagnostic value of DWI in characterizing ovarian tumors has been widely reported; however, data in pediatric and adolescent patients remain limited and inconsistent [ 17 ]. Furthermore, the application of DWI in children presents additional challenges related to age-dependent pelvic anatomy, motion artifacts, and the heterogeneous histological spectrum of pediatric ovarian tumors [ 18 ]. In particular, malignant epithelial ovarian tumors in children may demonstrate subtle or nonspecific morphological features on conventional MRI, increasing the risk of underestimation of malignant potential at early stages [ 19 ]. Given these diagnostic challenges, there is a clear need for comprehensive evaluation of both morphological and functional MRI parameters in pediatric ovarian tumors. Assessing the added value of DWI and quantitative ADC measurements may help refine preoperative diagnosis, reduce false-negative interpretations, and support more accurate risk stratification [ 20 ]. Therefore, the aim of this multicenter retrospective study was to evaluate the diagnostic performance of MRI in differentiating benign and malignant ovarian tumors in children and adolescents, with particular emphasis on the additional value of diffusion-weighted imaging and quantitative ADC analysis. Materials and Methods Study Design and Setting This multicenter retrospective observational study was conducted at two tertiary pediatric referral centers: the clinics of the Tashkent Pediatric Medical Institute and the Scientific and Practical Medical Center of Pediatric Oncology, Hematology and Immunology. The study period covered January 2020 to December 2025 . The study protocol was approved by the local institutional ethics committees of both participating centers. Due to the retrospective nature of the study, the requirement for informed consent was waived. This study was a retrospective observational study and was not a clinical trial. Patients A total of 152 children and adolescents with suspected ovarian tumors were initially evaluated during the study period. Of these, 96 patients underwent pelvic magnetic resonance imaging due to diagnostic uncertainty following ultrasound examination. Histopathological confirmation of diagnosis was available for all patients and served as the reference standard. Diffusion-weighted imaging with apparent diffusion coefficient (ADC) mapping was performed in 32 patients. According to histological findings, tumors were classified as benign or malignant, and various histological subtypes were included in the analysis. Inclusion criteria were: pediatric and adolescent patients with suspected ovarian tumors, availability of pelvic MRI examination, histopathological confirmation of diagnosis. Exclusion criteria were: absence of MRI data, incomplete imaging datasets, lack of histological verification. MRI Acquisition Protocol Pelvic MRI examinations were performed using 1.5-T and 3.0-T MRI scanners according to a standardized institutional protocol. The imaging protocol included axial, sagittal, and coronal sequences. Conventional MRI sequences comprised: T1-weighted images, T2-weighted images, fat-suppressed sequences when indicated. Diffusion-weighted imaging was performed in all patients with histologically confirmed tumors using multiple b-values (including b = 0 and b = 1000 s/mm²). Apparent diffusion coefficient (ADC) maps were automatically generated. Intravenous gadolinium-based contrast agents were administered when clinically indicated and when not contraindicated. Image Analysis All MRI examinations were retrospectively reviewed by experienced radiologists specializing in pediatric imaging. Image analysis was performed with consensus interpretation. The following morphological MRI features were evaluated: tumor size and location, internal architecture (cystic, solid, or cystic–solid), presence of solid components, tumor margins (smooth or irregular), extracapsular extension, presence of ascites, regional lymphadenopathy, peritoneal deposits, laterality (unilateral or bilateral involvement). Diffusion-Weighted Imaging and ADC Analysis DWI analysis was performed separately for cystic and solid tumor components. Circular regions of interest (ROIs) were manually placed within the most representative areas of the tumor, avoiding necrotic, hemorrhagic, and cystic regions when evaluating solid components. ADC measurements were obtained by averaging three separate ROI measurements. ADC values were expressed in ×10⁻³ mm²/s. Statistical Analysis Statistical analysis was performed using standard statistical software. Continuous variables were expressed as mean ± standard deviation or median with range, while categorical variables were presented as absolute numbers and percentages. Comparisons between benign and malignant tumors were conducted using appropriate statistical tests. A p-value < 0.05 was considered statistically significant. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic performance of MRI features and diffusion-weighted imaging. Sensitivity, specificity, and overall diagnostic accuracy were calculated using histopathological findings as the reference standard. Results Patient Characteristics During the study period, 152 children and adolescents with suspected ovarian tumors were evaluated at the two participating centers. Pelvic MRI was performed in 96 patients due to inconclusive ultrasound findings. Histopathological confirmation was available in 32 patients and served as the reference standard for diagnostic performance analysis. Among patients with histologically confirmed tumors, malignant ovarian tumors were diagnosed in 22 cases (68.8%), while benign tumors were identified in 10 cases (31.2%). Morphological MRI Findings Comparative analysis of conventional MRI features demonstrated significant differences between benign and malignant ovarian tumors. The presence of a solid component was observed in 68.8% of malignant tumors compared with 6.3% of benign lesions (p < 0.001). Irregular tumor margins were detected exclusively in malignant tumors (65.6%, p < 0.001), whereas benign tumors consistently demonstrated smooth and well-defined contours. Extracapsular extension was identified in 59.4% of malignant tumors and was not observed in benign lesions (p < 0.001). Ascites was present in 53.1% of malignant cases and absent in all benign tumors (p < 0.001). Regional lymphadenopathy was significantly more frequent in malignant tumors (50.0%) than in benign lesions (4.7%, p < 0.001). Peritoneal deposits were detected in 43.8% of malignant tumors and were not observed in benign tumors (p < 0.001). Cystic–solid tumor architecture was common in both groups and did not demonstrate a statistically significant association with malignancy (p = 0.56). Tumor size greater than 10 cm was observed in both benign and malignant tumors and did not reliably differentiate tumor behavior (p = 0.14). Bilateral ovarian involvement was identified exclusively in malignant tumors (12.5%, p = 0.04), indicating high specificity but limited sensitivity. Table 1 summarizes the frequency of key MRI features in benign and malignant ovarian tumors. Table 1 summarizes the frequency of key MRI features in benign and malignant ovarian tumors. MRI feature Benign tumors (n = 64), n (%) Malignant tumors (n = 32), n (%) p-value Solid component 4 (6.3) 22 (68.8) < 0.001 Cystic–solid architecture 33 (51.6) 18 (56.3) 0.56 Irregular margins 0 (0) 21 (65.6) < 0.001 Extracapsular extension 0 (0) 19 (59.4) < 0.001 Ascites 0 (0) 17 (53.1) < 0.001 Regional lymphadenopathy 3 (4.7) 16 (50.0) < 0.001 Peritoneal deposits 0 (0) 14 (43.8) 10 cm 33 (51.6) 22 (68.8) 0.14 Histological Distribution Among malignant ovarian tumors, germ cell tumors represented the predominant histological group, accounting for 71.9% of cases. Dysgerminomas were the most frequent subtype, followed by immature teratomas and other germ cell malignancies. Epithelial ovarian malignancies constituted 25.0% of malignant tumors and included mucinous, endometrioid, and papillary adenocarcinomas. Benign ovarian tumors were predominantly represented by mature teratomas, followed by serous and mucinous cystadenomas, as well as fibromas and thecoma-fibromas. Diffusion-Weighted Imaging and ADC Analysis Diffusion-weighted imaging analysis revealed marked differences between benign and malignant tumors, particularly within solid tumor components. Malignant tumors demonstrated increased signal intensity on high b-value diffusion-weighted images and corresponding reductions in apparent diffusion coefficient (ADC) values, consistent with restricted diffusion. Quantitative analysis showed that mean ADC values of the solid components were significantly lower in malignant tumors compared with benign lesions (0.8 ± 0.09 ×10⁻³ mm²/s vs. 1.2 ± 0.13 ×10⁻³ mm²/s, p = 0.019). In contrast, ADC values of cystic tumor components did not differ significantly between benign and malignant tumors (p > 0.05), reflecting free diffusion of fluid content. Table 2 presents ADC values of solid tumor components in benign and malignant ovarian tumors. Table 2 presents ADC values of solid tumor components in benign and malignant ovarian tumors. Group n ADC (×10⁻³ mm²/s), mean ± SD p-value Benign tumors 10 1.2 ± 0.13 0.019 Malignant tumors 22 0.8 ± 0.09 0.019 Diagnostic Performance of MRI and DWI Receiver operating characteristic (ROC) analysis demonstrated high diagnostic performance of MRI based on conventional morphological features, with an area under the curve (AUC) of 0.94. An optimal cutoff value of ≥ 4 MRI criteria yielded a sensitivity of 89.3%, specificity of 85.9%, and overall diagnostic accuracy of 87.0%. When diffusion-weighted imaging parameters were incorporated into the diagnostic assessment, overall diagnostic performance further improved. Combined morphological MRI and DWI analysis achieved a sensitivity of 91.0%, specificity of 88.0%, and diagnostic accuracy of 89.0%. False-negative results were primarily observed in early-stage malignant epithelial tumors lacking prominent solid components or signs of tumor spread. False-positive findings were mainly associated with benign tumors containing dense tissue elements, particularly mature teratomas, which may mimic diffusion restriction. Conclusions Magnetic resonance imaging is a highly informative modality for the evaluation of ovarian tumors in children and adolescents; however, the diagnostic performance of conventional morphological MRI criteria alone may be limited due to substantial overlap between benign and malignant lesions. In particular, tumor size and cystic–solid architecture were shown to have limited value as independent indicators of malignancy. MRI features reflecting invasive tumor behavior and disease spread—including the presence of solid components, irregular margins, extracapsular extension, ascites, regional lymphadenopathy, and peritoneal deposits—were significantly associated with malignant ovarian tumors and demonstrated the highest diagnostic relevance in the pediatric population. Diffusion-weighted imaging with quantitative apparent diffusion coefficient assessment provides significant additional diagnostic value, especially when evaluating solid tumor components. Lower ADC values were reliably associated with malignant tumors, reflecting higher cellularity and restricted diffusion, whereas ADC measurements of cystic components were not diagnostically informative. A comprehensive MRI approach combining morphological assessment with diffusion-weighted imaging significantly improves diagnostic accuracy, sensitivity, and specificity in differentiating benign and malignant ovarian tumors in children and adolescents. This integrated imaging strategy may enhance preoperative risk stratification, reduce diagnostic uncertainty—particularly in early-stage malignant epithelial tumors—and support optimal clinical decision-making aimed at oncological safety and preservation of reproductive potential in pediatric patients. Declarations Ethics approval and consent to participate The study was approved by the Ethics Committee of the Tashkent Pediatric Medical Institute. Due to the retrospective observational design of the study and the use of anonymized clinical and imaging data, the requirement for informed consent was waived by the Ethics Committee. Consent for publication Not applicable. Availability of data and materials The datasets generated and/or analyzed during the current study are not publicly available due to institutional and ethical restrictions related to patient confidentiality but are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding The authors received no specific funding for this study. Author Contributions G.Y. and M.K. conceived and designed the study. G.Y., U.U., L.S., and M.A. contributed to data collection and image analysis. M.K. performed the statistical analysis and drafted the manuscript. All authors critically revised the manuscript and approved the final version. References Schultz KA et al. Ovarian tumors in children and adolescents. Pediatr Blood Cancer. 2016. Cecchetto G. Ovarian tumors in children and adolescents. J Pediatr Surg. 2014. Cass DL et al. Management of ovarian masses in children and adolescents. J Pediatr Surg. 2001. Rogers PC et al. Fertility preservation in pediatric oncology. Lancet Oncol. 2014. Servaes S et al. Imaging of pediatric ovarian neoplasms. Radiographics. 2012. Valentin L. Pattern recognition of adnexal masses by ultrasound. Ultrasound Obstet Gynecol. 2013. Thomassin-Naggara I et al. Adnexal masses: MRI imaging. Radiology. 2013. Sohaib SA et al. Characterization of adnexal masses with MRI. AJR Am J Roentgenol. 2005. Kinkel K et al. Indeterminate ovarian mass: MRI. Radiology. 2000. Forstner R et al. ESUR recommendations for MRI of ovarian tumors. Eur Radiol. 2017. Outwater EK et al. Ovarian teratomas: MR imaging. Radiology. 2001. Levy AD et al. From the archives of AFIP: ovarian neoplasms. Radiographics. 2008. Sahdev A et al. The role of MRI in ovarian cancer. Clin Radiol. 2007. Koh DM, Collins DJ. Diffusion-weighted MRI in oncology. Eur Radiol. 2007. Thomassin-Naggara I et al. Diffusion-weighted MRI for ovarian tumors. Radiology. 2011. Fujii S et al. Diagnostic accuracy of ADC values in ovarian tumors. AJR. 2008. Kyriazi S et al. Diffusion-weighted imaging of ovarian cancer. Eur Radiol. 2010. Ghosh P et al. Pediatric pelvic MRI: challenges and pitfalls. Pediatr Radiol. 2019. Brown J et al. Malignant ovarian tumors in children. Gynecol Oncol. 2014. Li HM et al. Added value of DWI in ovarian tumors. Eur J Radiol. 2015. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 26 Mar, 2026 Read the published version in BMC Pediatrics → Version 1 posted Editorial decision: Revision requested 04 Mar, 2026 Reviews received at journal 04 Mar, 2026 Reviewers agreed at journal 02 Mar, 2026 Reviews received at journal 02 Mar, 2026 Reviewers agreed at journal 02 Mar, 2026 Reviewers agreed at journal 27 Feb, 2026 Reviewers agreed at journal 26 Feb, 2026 Reviewers agreed at journal 24 Feb, 2026 Reviewers agreed at journal 22 Feb, 2026 Reviewers agreed at journal 21 Feb, 2026 Reviewers agreed at journal 20 Feb, 2026 Reviewers invited by journal 20 Feb, 2026 Editor invited by journal 06 Feb, 2026 Editor assigned by journal 05 Feb, 2026 Submission checks completed at journal 05 Feb, 2026 First submitted to journal 28 Jan, 2026 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. 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Although ovarian neoplasms account for a small proportion of pediatric tumors, their timely and accurate diagnosis is essential, as delayed or incorrect assessment may lead to suboptimal treatment strategies, unnecessary radical surgery, and potential loss of reproductive function [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In pediatric patients, preservation of ovarian tissue and fertility remains a critical consideration alongside oncological safety [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eUltrasound is widely used as the first-line imaging modality for the evaluation of adnexal masses in children due to its availability, absence of ionizing radiation, and high sensitivity in detecting ovarian lesions [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, ultrasound findings are often nonspecific, particularly in cases of large, complex, or atypically located tumors. As a result, diagnostic uncertainty frequently persists, necessitating further imaging evaluation [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMagnetic resonance imaging (MRI) plays a pivotal role in the assessment of indeterminate ovarian masses in pediatric patients. Owing to its excellent soft-tissue contrast, multiplanar imaging capability, and lack of ionizing radiation, MRI is considered the most informative cross-sectional imaging technique for pelvic evaluation in children and adolescents [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Conventional MRI allows detailed assessment of tumor morphology, internal architecture, signal characteristics, and extent of disease, which are essential for preoperative planning [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite these advantages, differentiation between benign and malignant ovarian tumors based solely on conventional morphological MRI features remains challenging in pediatric practice [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Several imaging characteristics traditionally associated with malignancy\u0026mdash;such as the presence of solid components, heterogeneous signal intensity, irregular margins, and complex cystic\u0026ndash;solid architecture\u0026mdash;may also be observed in benign lesions, including mature teratomas and certain epithelial tumors [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. This overlap of imaging features significantly limits the specificity of standard morphological MRI assessment and may result in diagnostic ambiguity [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAdvanced MRI techniques, particularly diffusion-weighted imaging (DWI), have emerged as promising tools for improving diagnostic accuracy in oncologic imaging [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. DWI provides functional information related to tissue cellularity and microstructural organization by evaluating the diffusion of water molecules within tissues. Quantitative analysis using apparent diffusion coefficient (ADC) values allows objective assessment of diffusion restriction, which is typically more pronounced in highly cellular malignant tumors [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In adult populations, the diagnostic value of DWI in characterizing ovarian tumors has been widely reported; however, data in pediatric and adolescent patients remain limited and inconsistent [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFurthermore, the application of DWI in children presents additional challenges related to age-dependent pelvic anatomy, motion artifacts, and the heterogeneous histological spectrum of pediatric ovarian tumors [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In particular, malignant epithelial ovarian tumors in children may demonstrate subtle or nonspecific morphological features on conventional MRI, increasing the risk of underestimation of malignant potential at early stages [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGiven these diagnostic challenges, there is a clear need for comprehensive evaluation of both morphological and functional MRI parameters in pediatric ovarian tumors. Assessing the added value of DWI and quantitative ADC measurements may help refine preoperative diagnosis, reduce false-negative interpretations, and support more accurate risk stratification [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTherefore, the aim of this multicenter retrospective study was to evaluate the diagnostic performance of MRI in differentiating benign and malignant ovarian tumors in children and adolescents, with particular emphasis on the additional value of diffusion-weighted imaging and quantitative ADC analysis.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003ch3\u003e\u003cstrong\u003eStudy Design and Setting\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThis multicenter retrospective observational study was conducted at two tertiary pediatric referral centers: the clinics of the Tashkent Pediatric Medical Institute and the Scientific and Practical Medical Center of Pediatric Oncology, Hematology and Immunology. The study period covered January \u003cstrong\u003e2020 to December 2025\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study protocol was approved by the local institutional ethics committees of both participating centers. Due to the retrospective nature of the study, the requirement for informed consent was waived.\u003c/p\u003e\n\u003cp\u003eThis study was a retrospective observational study and was not a clinical trial.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003ePatients\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eA total of 152 children and adolescents with suspected ovarian tumors were initially evaluated during the study period. Of these, 96 patients underwent pelvic magnetic resonance imaging due to diagnostic uncertainty following ultrasound examination. Histopathological confirmation of diagnosis was available for all patients and served as the reference standard. Diffusion-weighted imaging with apparent diffusion coefficient (ADC) mapping was performed in 32 patients. According to histological findings, tumors were classified as benign or malignant, and various histological subtypes were included in the analysis.\u003c/p\u003e\n\u003cp\u003eInclusion criteria were:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003epediatric and adolescent patients with suspected ovarian tumors,\u003c/li\u003e\n \u003cli\u003eavailability of pelvic MRI examination,\u003c/li\u003e\n \u003cli\u003ehistopathological confirmation of diagnosis.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eExclusion criteria were:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eabsence of MRI data,\u003c/li\u003e\n \u003cli\u003eincomplete imaging datasets,\u003c/li\u003e\n \u003cli\u003elack of histological verification.\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eMRI Acquisition Protocol\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003ePelvic MRI examinations were performed using 1.5-T and 3.0-T MRI scanners according to a standardized institutional protocol. The imaging protocol included axial, sagittal, and coronal sequences.\u003c/p\u003e\n\u003cp\u003eConventional MRI sequences comprised:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eT1-weighted images,\u003c/li\u003e\n \u003cli\u003eT2-weighted images,\u003c/li\u003e\n \u003cli\u003efat-suppressed sequences when indicated.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eDiffusion-weighted imaging was performed in all patients with histologically confirmed tumors using multiple b-values (including b = 0 and b = 1000 s/mm²). Apparent diffusion coefficient (ADC) maps were automatically generated.\u003c/p\u003e\n\u003cp\u003eIntravenous gadolinium-based contrast agents were administered when clinically indicated and when not contraindicated.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eImage Analysis\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eAll MRI examinations were retrospectively reviewed by experienced radiologists specializing in pediatric imaging. Image analysis was performed with consensus interpretation.\u003c/p\u003e\n\u003cp\u003eThe following morphological MRI features were evaluated:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003etumor size and location,\u003c/li\u003e\n \u003cli\u003einternal architecture (cystic, solid, or cystic–solid),\u003c/li\u003e\n \u003cli\u003epresence of solid components,\u003c/li\u003e\n \u003cli\u003etumor margins (smooth or irregular),\u003c/li\u003e\n \u003cli\u003eextracapsular extension,\u003c/li\u003e\n \u003cli\u003epresence of ascites,\u003c/li\u003e\n \u003cli\u003eregional lymphadenopathy,\u003c/li\u003e\n \u003cli\u003eperitoneal deposits,\u003c/li\u003e\n \u003cli\u003elaterality (unilateral or bilateral involvement).\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eDiffusion-Weighted Imaging and ADC Analysis\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eDWI analysis was performed separately for cystic and solid tumor components. Circular regions of interest (ROIs) were manually placed within the most representative areas of the tumor, avoiding necrotic, hemorrhagic, and cystic regions when evaluating solid components.\u003c/p\u003e\n\u003cp\u003eADC measurements were obtained by averaging three separate ROI measurements. ADC values were expressed in ×10⁻³ mm²/s.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eStatistical analysis was performed using standard statistical software. Continuous variables were expressed as mean ± standard deviation or median with range, while categorical variables were presented as absolute numbers and percentages.\u003c/p\u003e\n\u003cp\u003eComparisons between benign and malignant tumors were conducted using appropriate statistical tests. A p-value \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e\n\u003cp\u003eReceiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic performance of MRI features and diffusion-weighted imaging. Sensitivity, specificity, and overall diagnostic accuracy were calculated using histopathological findings as the reference standard.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003ePatient Characteristics\u003c/h2\u003e \u003cp\u003eDuring the study period, 152 children and adolescents with suspected ovarian tumors were evaluated at the two participating centers. Pelvic MRI was performed in 96 patients due to inconclusive ultrasound findings. Histopathological confirmation was available in 32 patients and served as the reference standard for diagnostic performance analysis.\u003c/p\u003e \u003cp\u003eAmong patients with histologically confirmed tumors, malignant ovarian tumors were diagnosed in 22 cases (68.8%), while benign tumors were identified in 10 cases (31.2%).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eMorphological MRI Findings\u003c/h2\u003e \u003cp\u003eComparative analysis of conventional MRI features demonstrated significant differences between benign and malignant ovarian tumors. The presence of a solid component was observed in 68.8% of malignant tumors compared with 6.3% of benign lesions (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Irregular tumor margins were detected exclusively in malignant tumors (65.6%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), whereas benign tumors consistently demonstrated smooth and well-defined contours.\u003c/p\u003e \u003cp\u003eExtracapsular extension was identified in 59.4% of malignant tumors and was not observed in benign lesions (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Ascites was present in 53.1% of malignant cases and absent in all benign tumors (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Regional lymphadenopathy was significantly more frequent in malignant tumors (50.0%) than in benign lesions (4.7%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Peritoneal deposits were detected in 43.8% of malignant tumors and were not observed in benign tumors (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003eCystic\u0026ndash;solid tumor architecture was common in both groups and did not demonstrate a statistically significant association with malignancy (p\u0026thinsp;=\u0026thinsp;0.56). Tumor size greater than 10 cm was observed in both benign and malignant tumors and did not reliably differentiate tumor behavior (p\u0026thinsp;=\u0026thinsp;0.14). Bilateral ovarian involvement was identified exclusively in malignant tumors (12.5%, p\u0026thinsp;=\u0026thinsp;0.04), indicating high specificity but limited sensitivity. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e summarizes the frequency of key MRI features in benign and malignant ovarian tumors.\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\u003esummarizes the frequency of key MRI features in benign and malignant ovarian tumors.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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=\"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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMRI feature\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBenign tumors (n\u0026thinsp;=\u0026thinsp;64), n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMalignant tumors (n\u0026thinsp;=\u0026thinsp;32), n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\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\u003eSolid component\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (6.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e22 (68.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCystic\u0026ndash;solid architecture\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33 (51.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e18 (56.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.56\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIrregular margins\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e21 (65.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eExtracapsular extension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19 (59.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAscites\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e17 (53.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRegional lymphadenopathy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (4.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e16 (50.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePeritoneal deposits\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e14 (43.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBilateral ovarian involvement\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4 (12.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTumor size\u0026thinsp;\u0026gt;\u0026thinsp;10 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33 (51.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e22 (68.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.14\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eHistological Distribution\u003c/h2\u003e \u003cp\u003eAmong malignant ovarian tumors, germ cell tumors represented the predominant histological group, accounting for 71.9% of cases. Dysgerminomas were the most frequent subtype, followed by immature teratomas and other germ cell malignancies. Epithelial ovarian malignancies constituted 25.0% of malignant tumors and included mucinous, endometrioid, and papillary adenocarcinomas.\u003c/p\u003e \u003cp\u003eBenign ovarian tumors were predominantly represented by mature teratomas, followed by serous and mucinous cystadenomas, as well as fibromas and thecoma-fibromas.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eDiffusion-Weighted Imaging and ADC Analysis\u003c/h2\u003e \u003cp\u003eDiffusion-weighted imaging analysis revealed marked differences between benign and malignant tumors, particularly within solid tumor components. Malignant tumors demonstrated increased signal intensity on high b-value diffusion-weighted images and corresponding reductions in apparent diffusion coefficient (ADC) values, consistent with restricted diffusion.\u003c/p\u003e \u003cp\u003eQuantitative analysis showed that mean ADC values of the solid components were significantly lower in malignant tumors compared with benign lesions (0.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 \u0026times;10⁻\u0026sup3; mm\u0026sup2;/s vs. 1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 \u0026times;10⁻\u0026sup3; mm\u0026sup2;/s, p\u0026thinsp;=\u0026thinsp;0.019). In contrast, ADC values of cystic tumor components did not differ significantly between benign and malignant tumors (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05), reflecting free diffusion of fluid content. Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e presents ADC values of solid tumor components in benign and malignant ovarian tumors.\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\u003epresents ADC values of solid tumor components in benign and malignant ovarian tumors.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\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=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eADC (\u0026times;10⁻\u0026sup3; mm\u0026sup2;/s), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\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\u003eBenign tumors\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.019\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMalignant tumors\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cp\u003e0.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.019\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eDiagnostic Performance of MRI and DWI\u003c/h2\u003e \u003cp\u003eReceiver operating characteristic (ROC) analysis demonstrated high diagnostic performance of MRI based on conventional morphological features, with an area under the curve (AUC) of 0.94. An optimal cutoff value of \u0026ge;\u0026thinsp;4 MRI criteria yielded a sensitivity of 89.3%, specificity of 85.9%, and overall diagnostic accuracy of 87.0%.\u003c/p\u003e \u003cp\u003eWhen diffusion-weighted imaging parameters were incorporated into the diagnostic assessment, overall diagnostic performance further improved. Combined morphological MRI and DWI analysis achieved a sensitivity of 91.0%, specificity of 88.0%, and diagnostic accuracy of 89.0%.\u003c/p\u003e \u003cp\u003eFalse-negative results were primarily observed in early-stage malignant epithelial tumors lacking prominent solid components or signs of tumor spread. False-positive findings were mainly associated with benign tumors containing dense tissue elements, particularly mature teratomas, which may mimic diffusion restriction.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eMagnetic resonance imaging is a highly informative modality for the evaluation of ovarian tumors in children and adolescents; however, the diagnostic performance of conventional morphological MRI criteria alone may be limited due to substantial overlap between benign and malignant lesions. In particular, tumor size and cystic\u0026ndash;solid architecture were shown to have limited value as independent indicators of malignancy.\u003c/p\u003e \u003cp\u003eMRI features reflecting invasive tumor behavior and disease spread\u0026mdash;including the presence of solid components, irregular margins, extracapsular extension, ascites, regional lymphadenopathy, and peritoneal deposits\u0026mdash;were significantly associated with malignant ovarian tumors and demonstrated the highest diagnostic relevance in the pediatric population.\u003c/p\u003e \u003cp\u003eDiffusion-weighted imaging with quantitative apparent diffusion coefficient assessment provides significant additional diagnostic value, especially when evaluating solid tumor components. Lower ADC values were reliably associated with malignant tumors, reflecting higher cellularity and restricted diffusion, whereas ADC measurements of cystic components were not diagnostically informative.\u003c/p\u003e \u003cp\u003eA comprehensive MRI approach combining morphological assessment with diffusion-weighted imaging significantly improves diagnostic accuracy, sensitivity, and specificity in differentiating benign and malignant ovarian tumors in children and adolescents. This integrated imaging strategy may enhance preoperative risk stratification, reduce diagnostic uncertainty\u0026mdash;particularly in early-stage malignant epithelial tumors\u0026mdash;and support optimal clinical decision-making aimed at oncological safety and preservation of reproductive potential in pediatric patients.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch3\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThe study was approved by the Ethics Committee of the Tashkent Pediatric Medical Institute. Due to the retrospective observational design of the study and the use of anonymized clinical and imaging data, the requirement for informed consent was waived by the Ethics Committee.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during the current study are not publicly available due to institutional and ethical restrictions related to patient confidentiality but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThe authors received no specific funding for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eG.Y. and M.K. conceived and designed the study.\u003c/p\u003e\n\u003cp\u003eG.Y., U.U., L.S., and M.A. contributed to data collection and image analysis.\u003c/p\u003e\n\u003cp\u003eM.K. performed the statistical analysis and drafted the manuscript.\u003c/p\u003e\n\u003cp\u003eAll authors critically revised the manuscript and approved the final version.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSchultz KA et al. Ovarian tumors in children and adolescents. Pediatr Blood Cancer. 2016.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCecchetto G. Ovarian tumors in children and adolescents. J Pediatr Surg. 2014.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCass DL et al. Management of ovarian masses in children and adolescents. J Pediatr Surg. 2001.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRogers PC et al. Fertility preservation in pediatric oncology. Lancet Oncol. 2014.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eServaes S et al. Imaging of pediatric ovarian neoplasms. Radiographics. 2012.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eValentin L. Pattern recognition of adnexal masses by ultrasound. Ultrasound Obstet Gynecol. 2013.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThomassin-Naggara I et al. Adnexal masses: MRI imaging. Radiology. 2013.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSohaib SA et al. Characterization of adnexal masses with MRI. AJR Am J Roentgenol. 2005.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKinkel K et al. Indeterminate ovarian mass: MRI. Radiology. 2000.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eForstner R et al. ESUR recommendations for MRI of ovarian tumors. Eur Radiol. 2017.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOutwater EK et al. Ovarian teratomas: MR imaging. Radiology. 2001.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLevy AD et al. From the archives of AFIP: ovarian neoplasms. Radiographics. 2008.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSahdev A et al. The role of MRI in ovarian cancer. Clin Radiol. 2007.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoh DM, Collins DJ. Diffusion-weighted MRI in oncology. Eur Radiol. 2007.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThomassin-Naggara I et al. Diffusion-weighted MRI for ovarian tumors. Radiology. 2011.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFujii S et al. Diagnostic accuracy of ADC values in ovarian tumors. AJR. 2008.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKyriazi S et al. Diffusion-weighted imaging of ovarian cancer. Eur Radiol. 2010.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGhosh P et al. Pediatric pelvic MRI: challenges and pitfalls. Pediatr Radiol. 2019.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrown J et al. Malignant ovarian tumors in children. Gynecol Oncol. 2014.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi HM et al. Added value of DWI in ovarian tumors. Eur J Radiol. 2015.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Pediatric ovarian tumors, Magnetic resonance imaging, Diffusion-weighted imaging, Apparent diffusion coefficient, Benign and malignant tumors, Diagnostic accuracy","lastPublishedDoi":"10.21203/rs.3.rs-8727001/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8727001/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eOvarian tumors in children and adolescents represent a diagnostically challenging and heterogeneous group of diseases. Accurate preoperative differentiation between benign and malignant lesions is essential for optimal treatment planning and preservation of reproductive potential. Magnetic resonance imaging (MRI) plays a key role in the evaluation of indeterminate adnexal masses; however, conventional morphological MRI features often overlap between benign and malignant tumors. Diffusion-weighted imaging (DWI) may provide additional diagnostic information by reflecting tumor cellularity.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis multicenter retrospective observational study included pediatric patients with suspected ovarian tumors examined at two tertiary referral centers between 2020 and 2025. A total of 152 patients were evaluated, of whom 96 underwent pelvic MRI. Histopathological confirmation of diagnosis was available for all patients, while diffusion-weighted imaging with apparent diffusion coefficient (ADC) mapping was performed in 32 cases. MRI assessment included analysis of tumor morphology, presence of solid components, contour characteristics, extracapsular extension, ascites, lymphadenopathy, and peritoneal deposits. Diagnostic performance of MRI and DWI was assessed using receiver operating characteristic (ROC) analysis.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eSeveral morphological MRI features, including solid components, irregular margins, extracapsular growth, ascites, lymphadenopathy, and peritoneal deposits, were significantly more frequent in malignant tumors (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Tumor size and cystic\u0026ndash;solid architecture alone were not reliable indicators of malignancy. ADC values of the solid tumor component were significantly lower in malignant compared with benign lesions (0.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09 \u0026times;10⁻\u0026sup3; mm\u0026sup2;/s vs. 1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.13 \u0026times;10⁻\u0026sup3; mm\u0026sup2;/s, p\u0026thinsp;=\u0026thinsp;0.019). ROC analysis demonstrated high diagnostic accuracy of MRI based on morphological features (AUC\u0026thinsp;=\u0026thinsp;0.94). The combined use of morphological MRI and DWI improved diagnostic performance, with a sensitivity of 91.0%, specificity of 88.0%, and overall accuracy of 89.0%.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eMRI is a highly informative modality for the evaluation of ovarian tumors in children and adolescents; however, conventional morphological criteria alone may be insufficient, particularly in early-stage malignant epithelial tumors. Diffusion-weighted imaging with quantitative ADC assessment provides significant additional diagnostic value and improves differentiation between benign and malignant ovarian tumors. A comprehensive MRI approach incorporating both morphological and functional parameters may enhance diagnostic confidence and support optimal clinical decision-making in pediatric patients.\u003c/p\u003e","manuscriptTitle":"MRI Features and Diagnostic Value of Diffusion-Weighted Imaging in Pediatric Ovarian Tumors: A Multicenter Retrospective Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-24 18:50:55","doi":"10.21203/rs.3.rs-8727001/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-04T18:38:14+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-04T14:17:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"237551010536717363710232957950406697080","date":"2026-03-02T13:53:26+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-02T08:50:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"132320472156304752333314517023206867250","date":"2026-03-02T08:37:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"213497804154364865181163367267744895084","date":"2026-02-27T15:24:20+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"244309034620195098613167280679758825899","date":"2026-02-27T03:30:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"162256640212010582355712245638291165790","date":"2026-02-24T14:00:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"130614144903797255504834627192087361553","date":"2026-02-22T09:47:20+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"202506710832157492487368184055056142177","date":"2026-02-21T10:45:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"273545780961193002352913508690782026508","date":"2026-02-20T20:39:06+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-20T08:51:17+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-02-06T10:23:06+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-06T01:14:02+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-06T01:13:17+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pediatrics","date":"2026-01-29T04:31:07+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pediatrics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bped","sideBox":"Learn more about [BMC Pediatrics](http://bmcpediatr.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bped/default.aspx","title":"BMC Pediatrics","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"9a9b1f37-ab85-47b5-aa1b-6f35546930de","owner":[],"postedDate":"February 24th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-03-30T16:29:49+00:00","versionOfRecord":{"articleIdentity":"rs-8727001","link":"https://doi.org/10.1186/s12887-026-06783-w","journal":{"identity":"bmc-pediatrics","isVorOnly":false,"title":"BMC Pediatrics"},"publishedOn":"2026-03-26 16:08:51","publishedOnDateReadable":"March 26th, 2026"},"versionCreatedAt":"2026-02-24 18:50:55","video":"","vorDoi":"10.1186/s12887-026-06783-w","vorDoiUrl":"https://doi.org/10.1186/s12887-026-06783-w","workflowStages":[]},"version":"v1","identity":"rs-8727001","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8727001","identity":"rs-8727001","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}