Diagnostic Accuracy of Ultrasonography and Magnetic Resonance Imaging for FIGO Grading of Placenta Accreta Spectrum: A Histopathology-Based Study

Diagnostic Accuracy of Ultrasonography and Magnetic Resonance Imaging for FIGO Grading of Placenta Accreta Spectrum: A Histopathology-Based 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 Diagnostic Accuracy of Ultrasonography and Magnetic Resonance Imaging for FIGO Grading of Placenta Accreta Spectrum: A Histopathology-Based Study Leni Santiana, Dian Komala Dewi, Harry Galuh Nugraha, Khonsa Hartsu Syuhada, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8634583/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 The incidence of placenta accreta spectrum (PAS) has been increasing globally due to the increased rate of cesarean section. Radiology had a crucial role in PAS early diagnosis but the comparison studies between USG and MRI for PAS grading are lacking. This study aimed to compare USG and MRI with histopathology examination for placenta accreta invasion grading. This cross-sectional study was conducted in Hasan Sadikin Central General Hospital using medical records from January 2025 to June 2025. The USG and MRI results would be reviewed by radiologists or researchers for placental invasion grading based on the International Federation of Gynecology and Obstetrics (FIGO) classification. The diagnostic performance were determined using Statistical Package for Social Sciences (SPSS) software version 25.0. Twenty-four patients met the inclusion and exclusion criteria, with a mean age of 36.75 ± 4.46 years. Most PAS cases were FIGO III based on USG (58.3%) and MRI (41.7%), but based on the histopathologic results, most PAS cases were FIGO II (45.8%). The analysis revealed that MRI was superior to USG for PAS invasion grading (Cronbach's alpha 0.964 versus 0.521). Magnetic resonance imaging is crucial for PAS invasion grading, particularly if the USG was inconclusive or negative in high-risk pregnant women. Obstetrics & Gynecology Histopathology Magnetic Resonance Imaging Placenta Accreta Spectrum Ultrasonography Figures Figure 1 Teaching Point Magnetic Resonance Imaging can be done as an alternative diagnostic tools for PAS invasion grading. BACKGROUND Abnormally invasive placenta (AIP) or placenta accreta spectrum (PAS) is a disorder in which trophoblastic tissue penetrates the decidua basalis layer to the uterine myometrium, serosa, and spreads to the surrounding pelvic organs. It is classified into three types based on its invasion grades: placenta accreta (infiltration less than 50% of myometrium), increta (more than 50% myometrium), and percreta (protruding serosa to surrounding pelvic organs). The clinical diagnoses are made during surgery, but histopathological examination is the gold standard diagnostic examination. Currently, the terms placenta accreta and morbidly adherent placenta have been replaced by abnormal invasion of placenta or placenta accreta spectrum disorders to include invasion cases that are not only limited to myometrium but also extend beyond the uterus [1]. The AIP incidence has been increasing globally, particularly due to the increasing rate of caesarean from 1 per 2,500 pregnancies to 1 per 500 pregnancies. It is a worrisome condition because the morbidity and mortality risks of mothers and infants will also be affected, leading to prolonged length of stay and intensive care unit (ICU) stay, which also increases the incidence of post-traumatic stress disorder (PTSD) and psychological disorders. Placenta accreta spectrum accounts for 7 to 10% of the maternal mortality rate globally in the 1990s. However, this rate has been increasing due to prenatal diagnosis and management advancements. It is expected to decline continuously as clinicians become more experienced in detecting high-risk patients and the development of safer surgical management techniques [2]. An accurate prenatal diagnosis is the most crucial factor that affects clinical outcomes because underdiagnosis and overdiagnosis of PAS can lead to a serious condition. Early diagnosis offers an opportunity for optimal planning of surgery time and location. Obstetricians will also be able to prepare blood products and multidisciplinary surgical teams. Ultrasonography (USG) and Magnetic Resonance Imaging (MRI) are the main diagnostic tools for PAS diagnosis with their own disadvantages, highlighting the importance of radiology examination for PAS diagnosis. Ultrasonography remains the main diagnostic tool because it is relatively cheap and widely available. Furthermore, USG is routinely performed in 18–20 weeks of gestation that is an ideal time for screening for placental implantation disorders. The most useful USG findings for placenta accreta are placental lacunae with abnormal turbulent flow and a hypervascular area with widened blood vessels at the interface of placenta and myometrium [3]. The MRI application for placenta accreta evaluation has increased in recent years. It should be applied for cases with doubtful USG findings or an anterior placenta with risk factors. The MRI has an adjuvant role for a detailed description of the invasion extent in placenta percreta cases that have been identified through USG [4].The difference between the accuracy of USG (including colour Doppler) and MRI for placenta accreta diagnosis was not statistically significant. However, in high-risk patients, normal USG findings in 18–20 weeks of gestation cannot exclude placenta accreta completely. Therefore, re-evaluation in the third trimester is required. Overall, both USG and MRI are the safest diagnostic modalities for placenta accreta detection and an appropriate prenatal identification allows an optimum management. Magnetic resonance imaging is generally not required if USG shows negative findings because USG has a high negative predictive value. 5 However, comparison studies of USG and MRI in PAS diagnoses remain lacking and inconsistent even though this topic has a significant impact for PAS diagnosis and grading leading to decreased maternal and children morbidity and mortality. Therefore, this study aimed to assess the sensitivity and specificity of USG and MRI to determine the placenta accreta invasion grade based on the histopathologic findings in Hasan Sadikin Central General Hospital, Bandung, West Java. MATERIALS AND METHODS This cross-sectional study was conducted to determine the sensitivity and specificity of USG and MRI for placental accreta invasion grading based on histopathologic findings in Hasan Sadikin Central General Hospital, Bandung, West Java. Sampling was done in July 2025 – December 2025 using medical records from January 2025 – June 2025. This study had been approved by the Ethical Comittee before the data collection with a letter number of 185/UN6.C.6.29/PK.01/2025. The patients who agreed to participate in this study would sign informed consent form voluntarily. This study included adult women (aged more than 18 years old) with PAS who underwent USG and/or MRI in Hasan Sadikin Central General Hospital, Bandung, West Java from January 2025 to June 2025 who met inclusion and exclusion criteria. The inclusion criteria were: (1) Adult women (aged more than 18 years old) with clinical and/or radiology suspected PAS during pregnancy, (2) having USG and/or MRI in Hasan Sadikin Central General Hospital, (3) having delivery surgeries (sectio caesarea or hysterectomy) and histopathologic results from placental or uterine tissue, (4) having complete medical record including imaging and histopathologic results, and (5) gestational age of ≥ 28 weeks or were in the third trimester during imaging. The exclusion criteria were (1) patients with reading and writing difficulties or developmental delay that can inhibit or hinder the study; (2) the USG and MRI results were not completely documented or cannot be reviewed; (3) the patients were referred from other hospitals and underwent imaging in other health facilities; (4) their physical condition were not feasible to participate in this study, having emergency signs, unstable hemodynamics, or vital signs; and (5) they refused or did not give consent regarding their data utilization in this study. The collected variables were age, USG results, MRI results, and histopathologic results of placental and/or uterine tissue. Radiologists or researchers would review USG and MRI results for placental invasion grading based on International Federation of Gynecology and Obstetrics (FIGO) classification. The data normality were assessed using Kolmogorov-Smirnov test. Homogenity test was conducted using Leven test. All data underwent descriptive analysis. Categoric data were presented in frequency (n) and percentage (%). The numeric data were presented in mean and standard deviation (SD) if normally distributed or median and interquartile range (IQR) it not normally distributed. Sensitivitity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined using Statistical Package for Social Sciences (SPSS) software v25.0. RESULTS This was an observational study that compare the USG and MRI results with histopathologic results in PAS patients who were aged more than 18 years old. Out of the collected medical records from January to June 2025, 24 patients’ data met the inclusion and exclusion criteria in this study. The mean age of study participants were 36.75 ± 4.46 years. The baseline characteristic data were summarized in Table 1. The MRI, USG, and histopathologic results showed various findings. Most patients were diagnosed with FIGO III while histopathologic results revealed that most participants were diagnosed with FIGO II. The MRI and USG results were compared with histopathologic results with correlation and cronbach alpha test since histopathologic is the gold standard diagnosis of placenta accreta invasion grade. The comparison results were summarized in Tables 2 and 3. Table 2 showed nearly perfect results. The difference only found in FIGO III in which 2 MRI results showed FIGO III while histopathologic examination showed FIGO II. Furthermore, 8 of 10 patients with FIGO III MRI findings also have FIGO III histopathologic results. The FIGO I and II examination results have accuracy of 100% (Table 3). The analysis showed a significant Spearman Correlation with a p-value of < 0.005. Table 3 showed more variable results than Table 2. It may have occurred due to the USG that relies on the operator and revealed that MRI is superior to USG. The FIGO I USG results were only correct in 4 patients (40.0%) of all examined patients when compared to histopathologic results. Furthermore, patients with FIGO III USG results were only correct in 6 out of 14 patients with FIGO III histopathologic results (42.9%). The Spearman correlation test showed a weaker correlation with a coefficient of 0,076. The reliability was determined using Cronbach alpha test. Magnetic resonance imaging had score of 0.964 with inter-item correlation results of 0.932. It showed that MRI had an excellent reliability with histopathologic results. In other hand, USG had an inferior reliability with score of 0.521 and inter-item correlation of 0.379 that showed inferior reliability between USG results and histopathologic examination. We could conclude that MRI was way superior to USG for placenta accreta invasion grading based on histopathologic examination. Cronbach's alpha test revealed that MRI had a higher score than USG (0.964 versus 0.521). However, MRI is more expensive than USG; therefore, USG is more practical in daily practice. Skill upgrade and special attention were required in USG examination for placenta accreta invasion grading due to the higher risk of misdiagnosis compared to MRI. It was also influenced by the operator; therefore, the findings may vary according to the users’ skill. DISCUSSION Placenta accreta refers to a spectrum of placentation disorder that leads to partial or complete placenta retention during delivery. Traditionally, it is divided into three types, accreta, increta, and percreta, but this classification has not been used recently due to various grades of placental villi invasion into myometrium. Recently, experts have replaced the term placental accreta with placental accreta spectrum (PAS) that covers all grades of abnormal placentation descriptively with pathological grading classification proposed by FIGO (PAS grade 1–3E) (Fig. 1). Placental accreta spectrum covers morbidity adherent placenta (MAP) that includes placental accreta and abnormally invasive placenta (AIP) that includes placental increta and percreta [6–8]. The mean age of participants in this study was 36.75 ± 4.46 years. It is quite older compared to a study by Alavi et al in which the mean age of pregnant women with Pas was 33.86 ± 5.17 years, but in line with a study by Ornaghi et al., which showed that an age group of > 35 years old had a higher incidence of placenta accreta (52.1%) [8,9]. Older maternal age (> 35 years old) is associated with a higher risk of pregnancy complications, including placental accreta. The proliferation will increase with age, so the placenta will invade deeper into the myometrium and other organs. The prevalence of placenta accreta will increase by 2.2% with increasing maternal age. However, another study also revealed that maternal age did not correlate with PAS incidence; therefore, the correlation between those variables is still unknown [8,10]. This study found that most patients diagnosed with PAS FIGO III based on MRI and USG findings, while histopathologic examinations showed that most patients were diagnosed with PAS FIGO II. It is in line with a study by Morel et al, which revealed that most PAS cases that were detected by USG and MRI were FIGO III [11]. The pathologic PAS diagnosis was made based on the histopathologic examination by doing microscopic examination of placental villi and invasion or adhesion into the uterine myometrium. Histopathologic examination is the gold standard of PAS diagnosis, but histopathologic grading is not relevant to patients’ clinical condition and does not contribute to intra-operative management planning; therefore, FIGO classification was proposed for standardization of PAS clinical diagnosis report. Histopathologic examination has several disadvantages. First, the placental pathology sample can only be obtained from a partial uterine excision or resection specimen; therefore, this examination can only be conducted after surgery. Second, the same patient may have different results depending on the part of the tissue, particularly in the case of focal PAS with conservative surgery. Third, in severe PAS cases, particularly placenta percreta, histopathology experts may find it difficult to examine because the remaining myometrium is too thin [12.13]. Imaging is a screening tool for PAS identification and intrapartum management planning [12]. Early detection with USG and MRI is crucial for early detection of placental invasion before the tissue is removed, allowing clinicians to minimize post-surgery diagnosis that really relies on histopathologic examination [13]. Ultrasonography is the main diagnostic examination for prenatal PAS diagnosis. The initial finding of PAS in USG can be found in the first trimester of pregnancy, in which the gestational sac is in the lower segment of the uterus and near or below the section caesarean scar. Placental accreta spectrum should be suspected if pregnancy occurs in the scar of a cesarean scar. However, most PAS cases are not prenatally diagnosed. The most commonly used USG method is two-dimensional greyscale imaging characterized by multiple placental vascular lacunae or loss of "clear zone”. Both signs have similar accuracy for the Pas diagnosis, with a sensitivity value of more than 75% and a specificity of more than 95%. Three-dimensional ultrasound Doppler also contributes to PAS diagnosis [14]. A meta-analysis showed that USG has a sensitivity and specificity of 92% and 86%, respectively [15]. However, this study found that FIGO III diagnosis in USG was only correct in 6 out of 14 patients (42,9%). A study by Morel et al revealed that USG was less accurate in differentiating severe PAS (FIGO III) and mild-moderate (FIGO I-II) PAS. The sensitivity and specificity of USG for diagnosis are influenced by the operator because if the USG is used by experts, it is really accurate for PAS diagnosis, with sensitivity and specificity values reaching 90%. Otherwise, its sensitivity and specificity may decrease to 50% [11,12,16]. The MRI accuracy for PAS invasion grading may reach 100% for FIGO I–III. However, a study by More et al showed that MRI is less effective for severe PAS, and there is no evidence of MRI benefits for MRI invasion grading [11]. A study by Hong et al showed that MRI sensitivity and specificity for PAS diagnosis were 93% and 91%, respectively [15]. Magnetic resonance imaging has advantages over USG because MRI can be used to identify some difficult cases, for example, in posterior PAS, in which USG is less effective for this scenario. After all, the bladder cannot be used to identify the placenta-myometrium interface, while MRI can detect it. Furthermore, MRI has a better ability for PAS invasion grading, including how deeply the placenta penetrates the myometrium, parametrium, and bladder [14]. Other advantages of MRI are not limited by invasion depth, and can present multiplanar imaging with better soft tissue resolution [15]. The findings in this study highlighted the MRI potency for PAS invasion grading in clinical practice. The statistical test revealed that MRI has a better diagnostic performance compared to USG to determine the PAS invasion grade. Contrary to Hong et al and Craniello et al, who found that there was no significant difference between MRI and USG diagnostic performance for PAS diagnosis. However, a study by D’Antonio et al. found that MRI had better sensitivity than USG for PAS (94.4% versus 90.7%) [15,17]. This difference may occur because this study only includes pregnant women with gestational age over 28 weeks. The recommended time for PAS invasion grade screening using MRI is 24–33 weeks due to high false positive and negative values beyond that time range, while the optimum time for PAS evaluation using USG is 18–24 weeks. The placenta fully develops in the second and third trimester; therefore, MRI can assess the depth and extent of placental invasion, and anatomic structural imaging can be accurately compared to USG due to its high resolution. Furthermore, this study did not collect body mass index data and placental location because higher body mass index and posterior placenta can impair USG ability for PAS diagnosis. Small sample size, different reference of USG and MRI PAS signs, operator experiences, tools, and study design may be other confounding factors [13–15]. Magnetic resonance imaging is commonly recommended if clinicians suspect that PAS may have reached the surrounding pelvic organs, or the presence of USG confounding factors such as high body mass index and posterior placenta. The PAS signs in MRI are abnormal uterine protrusion, dark intraplacental ribbon in T2WI, bladder tenting, heterogeneous signal intensity in the placenta, unorganized placental vascular, and slight abnormality in myoplacenta. A systematic review and meta-analysis found that the sensitivity value of MRI to diagnose accreta placenta was 94.4%, 100% for placenta increta, and 86.5% for placenta percreta, while the specificity value for those conditions was 98.8%, 97.3%, and 96.8%, respectively. Studies also found that MRI is more beneficial for PAS invasion grading compared to USG. Some experts also conclude that MRI is more beneficial for characterization of placental invasion topography into the parametrium and other organs for better surgical planning, even though some guidelines have recommended MRI in some clinical scenarios, such as inconclusive USG findings or posterior placenta, but further studies are required [12,15] . Another advantage of MRI is that re-evaluation is feasible through consultation with other experts. The disadvantages of MRI are expensive and not available in all healthcare facilities, particularly in low- and middle-income countries. A study by Bartels et al found that MRI accuracy for PAS invasion grading can be enhanced by using radiomics. This study may strengthen that recommendation due to superior MRI diagnostic performance compared to USG. However, further standardization, optimization, and evidence of its reproducibility and advantages for PAS diagnosis are required [12,18]. This study has some limitations. First, a small sample size (24 samples). Second, correlation and multivariate analysis between age and PAS invasion grade were not conducted, so we did not know the correlation between those variables and whether age affect the sensitivity and specificity of USG and MRI. Third, demographic and other clinical data were not collected in order to determine the confounding factor of USG and MRI sensitivity and specificity for PAS invasion grading. CONCLUSION Magnetic Resonance Imaging is superior to USG for PAS invasion grading. This finding highlighted that MRI is crucial for PAS invasion grading, particularly if USG was inconclusive or negative in high-risk pregnant women. Abbreviations AIP Abnormally Invasive Placenta FIGO International Federation of Gynecology and Obstetrics IQR Interquartile Range MAP Morbidity Adherent Placenta MRI Magnetic Resonance Imaging PAS Placenta Accreta Spectrum PPV Positive Predictive Value NPV Negative Predictive Value USG Ultrasonography Declarations Authors' contributions LS: Conception and design of study, acquisition of data, data analysis and interpretation, literature searches, manuscript writing, and final manuscript approval; DKD: Design of study, acquisition of data, data analysis and interpretation, literature searches, manuscript writing, and final manuscript approval; HGN: Acquisition of data, data analysis and interpretation, literature searches, manuscript writing, and final manuscript approval; KHS: Data analysis and interpretation, manuscript writing, and final manuscript approval; AYP: Manuscript writing, and final manuscript approval; MHP: Manuscript writing, and final manuscript approval Acknowledgements None Disclosures This study had no conflict of interest and funding from any institution or organization. Consent Informed consent was obtained from participants prior data collection Human and animal rights This study had been approved by the Ethical Committee before the data collection with a letter number of 185/UN6.C.6.29/PK.01/2025. References Piñas Carrillo A, Chandraharan E. Placenta accreta spectrum: Risk factors, diagnosis and management with special reference to the Triple P procedure. Womens Health (Lond). 2019 Oct 3;15:1745506519878081. Jauniaux E, Grønbeck L, Bunce C, Langhoff-Roos J, Collins SL. Epidemiology of placenta previa accreta: a systematic review and meta-analysis. BMJ Open. 2019 Nov 12;9(11):e031193. Sawant R, Patil S, Warghade SS, Shirsat SY. The Role of Ultrasonography and Magnetic Resonance Imaging in the Diagnosis of the Adherent Placenta: An Observational Study. Cureus. 16(2):e53856. Varghese B, Singh N, George RAN, Gilvaz S. Magnetic resonance imaging of placenta accreta. Indian J Radiol Imaging. 2013;23(4):379–85. 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Ornaghi S, Maraschini A, Donati S, on behalf of The Regional Obstetric Surveillance System Working Group. Characteristics and outcomes of pregnant women with placenta accreta spectrum in Italy: A prospective population-based cohort study. Petry CJ, editor. PLoS ONE. 2021 Jun 4;16(6):e0252654. Hakim N dwihastuti, Dwi Izzati, Ernawati. Determinant Factors Affecting the Incidence of Placenta Accreta. Indonesian Midwifery and Health Sciences Journal. 2024;8(4):404–14. Morel O, van Beekhuizen HJ, Braun T, Collins S, Pateisky P, Calda P, et al. Performance of antenatal imaging to predict placenta accreta spectrum degree of severity. Acta Obstetricia et Gynecologica Scandinavica. 2021;100(S1):21–8. Self A, Cavallaro A, Collins SL. Placenta accreta spectrum: imaging and diagnosis. The Obstetrician & Gynaecologist. 2025;27(1):15–28. Chen Q, Shen K, Wu Y, Wei J, Huang J, Pei C. Advances in Prenatal Diagnosis of Placenta Accreta Spectrum. Medicina (Lithuania). 2025;61(3):1–15. Liu X, Wang Y, Wu Y, Zeng J, Yuan X, Tong C, et al. What we know about placenta accreta spectrum (PAS). European Journal of Obstetrics and Gynecology and Reproductive Biology. 2021;259(1):81–9. Hong S, Le Y, Lio KU, Zhang T, Zhang Y, Zhang N. Performance comparison of ultrasonography and magnetic resonance imaging in their diagnostic accuracy of placenta accreta spectrum disorders: a systematic review and meta-analysis. Insights into Imaging. 2022;13(1):50. Tsankova M, Kirkova M, Geshev N. Placenta accreta spectrum: ultrasound diagnosis and clinical correlation. Biotechnology and Biotechnological Equipment. 2023;37(1):2287238. De Oliveira Carniello M, Oliveira Brito LG, Sarian LO, Bennini JR. Diagnosis of placenta accreta spectrum in high-risk women using ultrasonography or magnetic resonance imaging: systematic review and meta-analysis. Ultrasound in Obstetrics and Gynecology. 2022;59(4):428–36. Bartels HC, O’Doherty J, Wolsztynski E, Brophy DP, MacDermott R, Atallah D, et al. Radiomics-based prediction of FIGO grade for placenta accreta spectrum. European Radiology Experimental. 2023;7(1):54. Tables Table 1. The Baseline Characteristic Data of Participants Variables Mean ± Standard Deviation / n (%) Age (years) 36.75 ± 4.46 MRI FIGO I FIGO II FIGO III 5 (20.8%) 9 (37.5%) 10 (41.7%) USG FIGO I FIGO II FIGO III 10 (41.7%) - 14 (58.3%) Histopathology FIGO I FIGO II FIGO III 5 (20.8%) 11 (45.8%) 8 (33.3%) Table 2. The Comparison between MRI Results and Histopathologic Results MRI Results Histopathologic Results Total FIGO I FIGO II FIGO III FIGO I 5 (100.0%) 0 (0.0%) 0 (0.0%) 5 (100.0%) FIGO II 0 (0.0%) 9 (100.0%) 0 (0.0%) 9 (100.0%) FIGO III 0 (0.0%) 2 (20.0%) 8 (80.0%) 10 (100.0%) Table 3. The Comparison between USG Results and Histopathologic Results USG Results Histopathologic Results Total FIGO I FIGO II FIGO III FIGO I 4 (40.0%) 4 (40.0%) 2 (20.0%) 10 (100.0%) FIGO III 1 (7.1%) 7 (50.0%) 6 (42.9%) 14 (100.0%) Additional Declarations The authors declare no competing interests. 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-8634583","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":576484579,"identity":"c779f33c-bacf-4872-b6ab-b3382264fde0","order_by":0,"name":"Leni Santiana","email":"","orcid":"","institution":"Department of Radiology, Faculty of Medicine, University of Padjadjaran, Dr. Hasan Sadikin General Centre Hospital, Bandung","correspondingAuthor":false,"prefix":"","firstName":"Leni","middleName":"","lastName":"Santiana","suffix":""},{"id":576484580,"identity":"e9346ecf-22dd-4704-a5dc-e7e98b74916e","order_by":1,"name":"Dian Komala 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10:30:50","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":776553,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8634583/v1/554855d4-41ad-42c2-b2ae-10b07b61af4b.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eDiagnostic Accuracy of Ultrasonography and Magnetic Resonance Imaging for FIGO Grading of Placenta Accreta Spectrum: A Histopathology-Based Study\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"Teaching Point","content":"\u003cp\u003eMagnetic Resonance Imaging can be done as an alternative diagnostic tools for PAS invasion grading.\u003c/p\u003e"},{"header":"BACKGROUND","content":"\u003cp\u003eAbnormally invasive placenta (AIP) or placenta accreta spectrum (PAS) is a disorder in which trophoblastic tissue penetrates the decidua basalis layer to the uterine myometrium, serosa, and spreads to the surrounding pelvic organs. It is classified into three types based on its invasion grades: placenta accreta (infiltration less than 50% of myometrium), increta (more than 50% myometrium), and percreta (protruding serosa to surrounding pelvic organs). The clinical diagnoses are made during surgery, but histopathological examination is the gold standard diagnostic examination. Currently, the terms placenta accreta and morbidly adherent placenta have been replaced by abnormal invasion of placenta or placenta accreta spectrum disorders to include invasion cases that are not only limited to myometrium but also extend beyond the uterus [1].\u003c/p\u003e\u003cp\u003eThe AIP incidence has been increasing globally, particularly due to the increasing rate of caesarean from 1 per 2,500 pregnancies to 1 per 500 pregnancies. It is a worrisome condition because the morbidity and mortality risks of mothers and infants will also be affected, leading to prolonged length of stay and intensive care unit (ICU) stay, which also increases the incidence of post-traumatic stress disorder (PTSD) and psychological disorders. Placenta accreta spectrum accounts for 7 to 10% of the maternal mortality rate globally in the 1990s. However, this rate has been increasing due to prenatal diagnosis and management advancements. It is expected to decline continuously as clinicians become more experienced in detecting high-risk patients and the development of safer surgical management techniques [2].\u003c/p\u003e\u003cp\u003eAn accurate prenatal diagnosis is the most crucial factor that affects clinical outcomes because underdiagnosis and overdiagnosis of PAS can lead to a serious condition. Early diagnosis offers an opportunity for optimal planning of surgery time and location. Obstetricians will also be able to prepare blood products and multidisciplinary surgical teams. Ultrasonography (USG) and Magnetic Resonance Imaging (MRI) are the main diagnostic tools for PAS diagnosis with their own disadvantages, highlighting the importance of radiology examination for PAS diagnosis. Ultrasonography remains the main diagnostic tool because it is relatively cheap and widely available. Furthermore, USG is routinely performed in 18–20 weeks of gestation that is an ideal time for screening for placental implantation disorders. The most useful USG findings for placenta accreta are placental lacunae with abnormal turbulent flow and a hypervascular area with widened blood vessels at the interface of placenta and myometrium [3].\u003c/p\u003e\u003cp\u003eThe MRI application for placenta accreta evaluation has increased in recent years. It should be applied for cases with doubtful USG findings or an anterior placenta with risk factors. The MRI has an adjuvant role for a detailed description of the invasion extent in placenta percreta cases that have been identified through USG [4].The difference between the accuracy of USG (including colour Doppler) and MRI for placenta accreta diagnosis was not statistically significant. However, in high-risk patients, normal USG findings in 18–20 weeks of gestation cannot exclude placenta accreta completely. Therefore, re-evaluation in the third trimester is required. Overall, both USG and MRI are the safest diagnostic modalities for placenta accreta detection and an appropriate prenatal identification allows an optimum management. Magnetic resonance imaging is generally not required if USG shows negative findings because USG has a high negative predictive value. \u003csup\u003e5\u003c/sup\u003e However, comparison studies of USG and MRI in PAS diagnoses remain lacking and inconsistent even though this topic has a significant impact for PAS diagnosis and grading leading to decreased maternal and children morbidity and mortality. Therefore, this study aimed to assess the sensitivity and specificity of USG and MRI to determine the placenta accreta invasion grade based on the histopathologic findings in Hasan Sadikin Central General Hospital, Bandung, West Java.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003eThis cross-sectional study was conducted to determine the sensitivity and specificity of USG and MRI for placental accreta invasion grading based on histopathologic findings in Hasan Sadikin Central General Hospital, Bandung, West Java. Sampling was done in July 2025 – December 2025 using medical records from January 2025 – June 2025. This study had been approved by the Ethical Comittee before the data collection with a letter number of 185/UN6.C.6.29/PK.01/2025. The patients who agreed to participate in this study would sign informed consent form voluntarily.\u003c/p\u003e\u003cp\u003eThis study included adult women (aged more than 18 years old) with PAS who underwent USG and/or MRI in Hasan Sadikin Central General Hospital, Bandung, West Java from January 2025 to June 2025 who met inclusion and exclusion criteria. The inclusion criteria were: (1) Adult women (aged more than 18 years old) with clinical and/or radiology suspected PAS during pregnancy, (2) having USG and/or MRI in Hasan Sadikin Central General Hospital, (3) having delivery surgeries (sectio caesarea or hysterectomy) and histopathologic results from placental or uterine tissue, (4) having complete medical record including imaging and histopathologic results, and (5) gestational age of \u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e≥\u003c/span\u003e 28 weeks or were in the third trimester during imaging. The exclusion criteria were (1) patients with reading and writing difficulties or developmental delay that can inhibit or hinder the study; (2) the USG and MRI results were not completely documented or cannot be reviewed; (3) the patients were referred from other hospitals and underwent imaging in other health facilities; (4) their physical condition were not feasible to participate in this study, having emergency signs, unstable hemodynamics, or vital signs; and (5) they refused or did not give consent regarding their data utilization in this study.\u003c/p\u003e\u003cp\u003eThe collected variables were age, USG results, MRI results, and histopathologic results of placental and/or uterine tissue. Radiologists or researchers would review USG and MRI results for placental invasion grading based on International Federation of Gynecology and Obstetrics (FIGO) classification. The data normality were assessed using Kolmogorov-Smirnov test. Homogenity test was conducted using Leven test. All data underwent descriptive analysis. Categoric data were presented in frequency (n) and percentage (%). The numeric data were presented in mean and standard deviation (SD) if normally distributed or median and interquartile range (IQR) it not normally distributed. Sensitivitity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined using Statistical Package for Social Sciences (SPSS) software v25.0.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eThis was an observational study that compare the USG and MRI results with histopathologic results in PAS patients who were aged more than 18 years old. Out of the collected medical records from January to June 2025, 24 patients’ data met the inclusion and exclusion criteria in this study. The mean age of study participants were 36.75 ± 4.46 years. The baseline characteristic data were summarized in Table\u0026nbsp;1.\u003c/p\u003e\u003cp\u003eThe MRI, USG, and histopathologic results showed various findings. Most patients were diagnosed with FIGO III while histopathologic results revealed that most participants were diagnosed with FIGO II. The MRI and USG results were compared with histopathologic results with correlation and cronbach alpha test since histopathologic is the gold standard diagnosis of placenta accreta invasion grade. The comparison results were summarized in Tables\u0026nbsp;2 and 3.\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;2 showed nearly perfect results. The difference only found in FIGO III in which 2 MRI results showed FIGO III while histopathologic examination showed FIGO II. Furthermore, 8 of 10 patients with FIGO III MRI findings also have FIGO III histopathologic results. The FIGO I and II examination results have accuracy of 100% (Table\u0026nbsp;3). The analysis showed a significant Spearman Correlation with a p-value of \u0026lt; 0.005.\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;3 showed more variable results than Table\u0026nbsp;2. It may have occurred due to the USG that relies on the operator and revealed that MRI is superior to USG. The FIGO I USG results were only correct in 4 patients (40.0%) of all examined patients when compared to histopathologic results. Furthermore, patients with FIGO III USG results were only correct in 6 out of 14 patients with FIGO III histopathologic results (42.9%). The Spearman correlation test showed a weaker correlation with a coefficient of 0,076.\u003c/p\u003e\u003cp\u003eThe reliability was determined using Cronbach alpha test. Magnetic resonance imaging had score of 0.964 with inter-item correlation results of 0.932. It showed that MRI had an excellent reliability with histopathologic results. In other hand, USG had an inferior reliability with score of 0.521 and inter-item correlation of 0.379 that showed inferior reliability between USG results and histopathologic examination.\u003c/p\u003e\u003cp\u003eWe could conclude that MRI was way superior to USG for placenta accreta invasion grading based on histopathologic examination. Cronbach's alpha test revealed that MRI had a higher score than USG (0.964 versus 0.521). However, MRI is more expensive than USG; therefore, USG is more practical in daily practice. Skill upgrade and special attention were required in USG examination for placenta accreta invasion grading due to the higher risk of misdiagnosis compared to MRI. It was also influenced by the operator; therefore, the findings may vary according to the users’ skill.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003ePlacenta accreta refers to a spectrum of placentation disorder that leads to partial or complete placenta retention during delivery. Traditionally, it is divided into three types, accreta, increta, and percreta, but this classification has not been used recently due to various grades of placental villi invasion into myometrium. Recently, experts have replaced the term placental accreta with placental accreta spectrum (PAS) that covers all grades of abnormal placentation descriptively with pathological grading classification proposed by FIGO (PAS grade 1–3E) (Fig.\u0026nbsp;1). Placental accreta spectrum covers morbidity adherent placenta (MAP) that includes placental accreta and abnormally invasive placenta (AIP) that includes placental increta and percreta [6–8].\u003c/p\u003e\u003cp\u003eThe mean age of participants in this study was 36.75 ± 4.46 years. It is quite older compared to a study by Alavi et al in which the mean age of pregnant women with Pas was 33.86 ± 5.17 years, but in line with a study by Ornaghi et al., which showed that an age group of \u0026gt; 35 years old had a higher incidence of placenta accreta (52.1%) [8,9]. Older maternal age (\u0026gt; 35 years old) is associated with a higher risk of pregnancy complications, including placental accreta. The proliferation will increase with age, so the placenta will invade deeper into the myometrium and other organs. The prevalence of placenta accreta will increase by 2.2% with increasing maternal age. However, another study also revealed that maternal age did not correlate with PAS incidence; therefore, the correlation between those variables is still unknown [8,10].\u003c/p\u003e\u003cp\u003eThis study found that most patients diagnosed with PAS FIGO III based on MRI and USG findings, while histopathologic examinations showed that most patients were diagnosed with PAS FIGO II. It is in line with a study by Morel et al, which revealed that most PAS cases that were detected by USG and MRI were FIGO III [11]. The pathologic PAS diagnosis was made based on the histopathologic examination by doing microscopic examination of placental villi and invasion or adhesion into the uterine myometrium. Histopathologic examination is the gold standard of PAS diagnosis, but histopathologic grading is not relevant to patients’ clinical condition and does not contribute to intra-operative management planning; therefore, FIGO classification was proposed for standardization of PAS clinical diagnosis report. Histopathologic examination has several disadvantages. First, the placental pathology sample can only be obtained from a partial uterine excision or resection specimen; therefore, this examination can only be conducted after surgery. Second, the same patient may have different results depending on the part of the tissue, particularly in the case of focal PAS with conservative surgery. Third, in severe PAS cases, particularly placenta percreta, histopathology experts may find it difficult to examine because the remaining myometrium is too thin [12.13].\u003c/p\u003e\u003cp\u003eImaging is a screening tool for PAS identification and intrapartum management planning [12]. Early detection with USG and MRI is crucial for early detection of placental invasion before the tissue is removed, allowing clinicians to minimize post-surgery diagnosis that really relies on histopathologic examination [13]. Ultrasonography is the main diagnostic examination for prenatal PAS diagnosis. The initial finding of PAS in USG can be found in the first trimester of pregnancy, in which the gestational sac is in the lower segment of the uterus and near or below the section caesarean scar. Placental accreta spectrum should be suspected if pregnancy occurs in the scar of a cesarean scar. However, most PAS cases are not prenatally diagnosed. The most commonly used USG method is two-dimensional greyscale imaging characterized by multiple placental vascular lacunae or loss of \"clear zone”. Both signs have similar accuracy for the Pas diagnosis, with a sensitivity value of more than 75% and a specificity of more than 95%. Three-dimensional ultrasound Doppler also contributes to PAS diagnosis [14]. A meta-analysis showed that USG has a sensitivity and specificity of 92% and 86%, respectively [15]. However, this study found that FIGO III diagnosis in USG was only correct in 6 out of 14 patients (42,9%). A study by Morel et al revealed that USG was less accurate in differentiating severe PAS (FIGO III) and mild-moderate (FIGO I-II) PAS. The sensitivity and specificity of USG for diagnosis are influenced by the operator because if the USG is used by experts, it is really accurate for PAS diagnosis, with sensitivity and specificity values reaching 90%. Otherwise, its sensitivity and specificity may decrease to 50% [11,12,16].\u003c/p\u003e\u003cp\u003eThe MRI accuracy for PAS invasion grading may reach 100% for FIGO I–III. However, a study by More et al showed that MRI is less effective for severe PAS, and there is no evidence of MRI benefits for MRI invasion grading [11]. A study by Hong et al showed that MRI sensitivity and specificity for PAS diagnosis were 93% and 91%, respectively [15]. Magnetic resonance imaging has advantages over USG because MRI can be used to identify some difficult cases, for example, in posterior PAS, in which USG is less effective for this scenario. After all, the bladder cannot be used to identify the placenta-myometrium interface, while MRI can detect it. Furthermore, MRI has a better ability for PAS invasion grading, including how deeply the placenta penetrates the myometrium, parametrium, and bladder [14]. Other advantages of MRI are not limited by invasion depth, and can present multiplanar imaging with better soft tissue resolution [15]. The findings in this study highlighted the MRI potency for PAS invasion grading in clinical practice.\u003c/p\u003e\u003cp\u003eThe statistical test revealed that MRI has a better diagnostic performance compared to USG to determine the PAS invasion grade. Contrary to Hong et al and Craniello et al, who found that there was no significant difference between MRI and USG diagnostic performance for PAS diagnosis. However, a study by D’Antonio et al. found that MRI had better sensitivity than USG for PAS (94.4% versus 90.7%) [15,17]. This difference may occur because this study only includes pregnant women with gestational age over 28 weeks. The recommended time for PAS invasion grade screening using MRI is 24–33 weeks due to high false positive and negative values beyond that time range, while the optimum time for PAS evaluation using USG is 18–24 weeks. The placenta fully develops in the second and third trimester; therefore, MRI can assess the depth and extent of placental invasion, and anatomic structural imaging can be accurately compared to USG due to its high resolution. Furthermore, this study did not collect body mass index data and placental location because higher body mass index and posterior placenta can impair USG ability for PAS diagnosis. Small sample size, different reference of USG and MRI PAS signs, operator experiences, tools, and study design may be other confounding factors [13–15].\u003c/p\u003e\u003cp\u003eMagnetic resonance imaging is commonly recommended if clinicians suspect that PAS may have reached the surrounding pelvic organs, or the presence of USG confounding factors such as high body mass index and posterior placenta. The PAS signs in MRI are abnormal uterine protrusion, dark intraplacental ribbon in T2WI, bladder tenting, heterogeneous signal intensity in the placenta, unorganized placental vascular, and slight abnormality in myoplacenta. A systematic review and meta-analysis found that the sensitivity value of MRI to diagnose accreta placenta was 94.4%, 100% for placenta increta, and 86.5% for placenta percreta, while the specificity value for those conditions was 98.8%, 97.3%, and 96.8%, respectively. Studies also found that MRI is more beneficial for PAS invasion grading compared to USG. Some experts also conclude that MRI is more beneficial for characterization of placental invasion topography into the parametrium and other organs for better surgical planning, even though some guidelines have recommended MRI in some clinical scenarios, such as inconclusive USG findings or posterior placenta, but further studies are required [12,15] .\u003c/p\u003e\u003cp\u003eAnother advantage of MRI is that re-evaluation is feasible through consultation with other experts. The disadvantages of MRI are expensive and not available in all healthcare facilities, particularly in low- and middle-income countries. A study by Bartels et al found that MRI accuracy for PAS invasion grading can be enhanced by using radiomics. This study may strengthen that recommendation due to superior MRI diagnostic performance compared to USG. However, further standardization, optimization, and evidence of its reproducibility and advantages for PAS diagnosis are required [12,18].\u003c/p\u003e\u003cp\u003eThis study has some limitations. First, a small sample size (24 samples). Second, correlation and multivariate analysis between age and PAS invasion grade were not conducted, so we did not know the correlation between those variables and whether age affect the sensitivity and specificity of USG and MRI. Third, demographic and other clinical data were not collected in order to determine the confounding factor of USG and MRI sensitivity and specificity for PAS invasion grading.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eMagnetic Resonance Imaging is superior to USG for PAS invasion grading. This finding highlighted that MRI is crucial for PAS invasion grading, particularly if USG was inconclusive or negative in high-risk pregnant women.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAIP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAbnormally Invasive Placenta\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFIGO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInternational Federation of Gynecology and Obstetrics\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIQR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInterquartile Range\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMAP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMorbidity Adherent Placenta\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMRI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMagnetic Resonance Imaging\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePAS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePlacenta Accreta Spectrum\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePPV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePositive Predictive Value\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNPV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNegative Predictive Value\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eUSG\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eUltrasonography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLS: Conception and design of study, acquisition of data, data analysis and interpretation, literature searches, manuscript writing, and final manuscript approval; DKD: Design of study, acquisition of data, data analysis and interpretation, literature searches, manuscript writing, and final manuscript approval; HGN: Acquisition of data, data analysis and interpretation, literature searches, manuscript writing, and final manuscript approval; KHS: Data analysis and interpretation, manuscript writing, and final manuscript approval; AYP: Manuscript writing, and final manuscript approval; MHP: Manuscript writing, and final manuscript approval\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDisclosures\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study had no conflict of interest and funding from any institution or organization.\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eConsent\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from participants prior data collection\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHuman and animal rights\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study had been approved by the Ethical Committee before the data collection with a letter number of 185/UN6.C.6.29/PK.01/2025.\u003c/p\u003e\n\n"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003ePi\u0026ntilde;as Carrillo A, Chandraharan E. Placenta accreta spectrum: Risk factors, diagnosis and management with special reference to the Triple P procedure. Womens Health (Lond). 2019 Oct 3;15:1745506519878081. \u003c/li\u003e\n\u003cli\u003eJauniaux E, Gr\u0026oslash;nbeck L, Bunce C, Langhoff-Roos J, Collins SL. Epidemiology of placenta previa accreta: a systematic review and meta-analysis. BMJ Open. 2019 Nov 12;9(11):e031193. \u003c/li\u003e\n\u003cli\u003eSawant R, Patil S, Warghade SS, Shirsat SY. The Role of Ultrasonography and Magnetic Resonance Imaging in the Diagnosis of the Adherent Placenta: An Observational Study. Cureus. 16(2):e53856. \u003c/li\u003e\n\u003cli\u003eVarghese B, Singh N, George RAN, Gilvaz S. Magnetic resonance imaging of placenta accreta. Indian J Radiol Imaging. 2013;23(4):379\u0026ndash;85. \u003c/li\u003e\n\u003cli\u003eThiravit S, Ma K, Goldman I, Chanprapaph P, Jha P, Hippe DS, et al. Role of Ultrasound and MRI in Diagnosis of Severe Placenta Accreta Spectrum Disorder: An Intraindividual Assessment With Emphasis on Placental Bulge. AJR Am J Roentgenol. 2021 Dec;217(6):1377\u0026ndash;88. \u003c/li\u003e\n\u003cli\u003eArakaza A, Zou L, Zhu J. Placenta Accreta Spectrum Diagnosis Challenges and Controversies in Current Obstetrics: A Review. International Journal of Women\u0026rsquo;s Health. 2023;15(April):635\u0026ndash;54. \u003c/li\u003e\n\u003cli\u003eKapoor H, Hanaoka M, Dawkins A, Khurana A. Review of MRI imaging for placenta accreta spectrum: Pathophysiologic insights, imaging signs, and recent developments. Placenta. 2021;104(November 2020):31\u0026ndash;9. \u003c/li\u003e\n\u003cli\u003eAlavi SM, Arjmandnia MH, Feizollahjani M, Noori E, Yousefi M. Placenta Accreta Spectrum; Risk Factors, Complications, Advantages and Disadvantages to Decrease Maternal Morbidity and Mortality. Journal of Obstetrics, Gynecology and Cancer Research. 2024;9(5):516\u0026ndash;21. \u003c/li\u003e\n\u003cli\u003eOrnaghi S, Maraschini A, Donati S, on behalf of The Regional Obstetric Surveillance System Working Group. Characteristics and outcomes of pregnant women with placenta accreta spectrum in Italy: A prospective population-based cohort study. Petry CJ, editor. PLoS ONE. 2021 Jun 4;16(6):e0252654. \u003c/li\u003e\n\u003cli\u003eHakim N dwihastuti, Dwi Izzati, Ernawati. Determinant Factors Affecting the Incidence of Placenta Accreta. Indonesian Midwifery and Health Sciences Journal. 2024;8(4):404\u0026ndash;14. \u003c/li\u003e\n\u003cli\u003eMorel O, van Beekhuizen HJ, Braun T, Collins S, Pateisky P, Calda P, et al. Performance of antenatal imaging to predict placenta accreta spectrum degree of severity. Acta Obstetricia et Gynecologica Scandinavica. 2021;100(S1):21\u0026ndash;8. \u003c/li\u003e\n\u003cli\u003eSelf A, Cavallaro A, Collins SL. Placenta accreta spectrum: imaging and diagnosis. The Obstetrician \u0026amp; Gynaecologist. 2025;27(1):15\u0026ndash;28. \u003c/li\u003e\n\u003cli\u003eChen Q, Shen K, Wu Y, Wei J, Huang J, Pei C. Advances in Prenatal Diagnosis of Placenta Accreta Spectrum. Medicina (Lithuania). 2025;61(3):1\u0026ndash;15. \u003c/li\u003e\n\u003cli\u003eLiu X, Wang Y, Wu Y, Zeng J, Yuan X, Tong C, et al. What we know about placenta accreta spectrum (PAS). European Journal of Obstetrics and Gynecology and Reproductive Biology. 2021;259(1):81\u0026ndash;9. \u003c/li\u003e\n\u003cli\u003eHong S, Le Y, Lio KU, Zhang T, Zhang Y, Zhang N. Performance comparison of ultrasonography and magnetic resonance imaging in their diagnostic accuracy of placenta accreta spectrum disorders: a systematic review and meta-analysis. Insights into Imaging. 2022;13(1):50. \u003c/li\u003e\n\u003cli\u003eTsankova M, Kirkova M, Geshev N. Placenta accreta spectrum: ultrasound diagnosis and clinical correlation. Biotechnology and Biotechnological Equipment. 2023;37(1):2287238. \u003c/li\u003e\n\u003cli\u003eDe Oliveira Carniello M, Oliveira Brito LG, Sarian LO, Bennini JR. Diagnosis of placenta accreta spectrum in high-risk women using ultrasonography or magnetic resonance imaging: systematic review and meta-analysis. Ultrasound in Obstetrics and Gynecology. 2022;59(4):428\u0026ndash;36. \u003c/li\u003e\n\u003cli\u003eBartels HC, O\u0026rsquo;Doherty J, Wolsztynski E, Brophy DP, MacDermott R, Atallah D, et al. Radiomics-based prediction of FIGO grade for placenta accreta spectrum. European Radiology Experimental. 2023;7(1):54. \u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 1.\u0026nbsp;\u003c/strong\u003eThe Baseline Characteristic Data of Participants\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eVariables\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMean \u0026nbsp;\u0026plusmn; Standard Deviation / n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003eAge (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e36.75 \u0026plusmn; 4.46\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003eMRI\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO I\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO II\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO III\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e5 (20.8%)\u003c/p\u003e\n \u003cp\u003e9 (37.5%)\u003c/p\u003e\n \u003cp\u003e10 (41.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003eUSG\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO I\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO II\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO III\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e10 (41.7%)\u003c/p\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003cp\u003e14 (58.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 34px;\"\u003e\n \u003cp\u003eHistopathology\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO I\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO II\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;FIGO III\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e5 (20.8%)\u003c/p\u003e\n \u003cp\u003e11 (45.8%)\u003c/p\u003e\n \u003cp\u003e8 (33.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 2.\u0026nbsp;\u003c/strong\u003eThe Comparison \u0026nbsp;between MRI Results and Histopathologic Results\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMRI Results\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;Histopathologic Results\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTotal\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFIGO I\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFIGO II\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFIGO III\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003eFIGO I\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e5 (100.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e5 (100.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003eFIGO II\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e9 (100.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e9 (100.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003eFIGO III\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e2 (20.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e8 (80.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e10 (100.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" valign=\"top\" style=\"width: 100px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 3.\u0026nbsp;\u003c/strong\u003eThe Comparison between USG Results and Histopathologic Results\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eUSG Results\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eHistopathologic Results\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTotal\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFIGO I\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFIGO II\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eFIGO III\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003eFIGO I\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e4 (40.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e4 (40.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e2 (20.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e10 (100.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003eFIGO III\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e1 (7.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e7 (50.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e6 (42.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20px;\"\u003e\n \u003cp\u003e14 (100.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Padjadjaran University","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":"Histopathology, Magnetic Resonance Imaging, Placenta Accreta Spectrum, Ultrasonography","lastPublishedDoi":"10.21203/rs.3.rs-8634583/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8634583/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe incidence of placenta accreta spectrum (PAS) has been increasing globally due to the increased rate of cesarean section. Radiology had a crucial role in PAS early diagnosis but the comparison studies between USG and MRI for PAS grading are lacking. This study aimed to compare USG and MRI with histopathology examination for placenta accreta invasion grading. This cross-sectional study was conducted in Hasan Sadikin Central General Hospital using medical records from January 2025 to June 2025. The USG and MRI results would be reviewed by radiologists or researchers for placental invasion grading based on the International Federation of Gynecology and Obstetrics (FIGO) classification. The diagnostic performance were determined using Statistical Package for Social Sciences (SPSS) software version 25.0. Twenty-four patients met the inclusion and exclusion criteria, with a mean age of 36.75\u0026thinsp;\u0026plusmn;\u0026thinsp;4.46 years. Most PAS cases were FIGO III based on USG (58.3%) and MRI (41.7%), but based on the histopathologic results, most PAS cases were FIGO II (45.8%). The analysis revealed that MRI was superior to USG for PAS invasion grading (Cronbach's alpha 0.964 versus 0.521). Magnetic resonance imaging is crucial for PAS invasion grading, particularly if the USG was inconclusive or negative in high-risk pregnant women.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e","manuscriptTitle":"Diagnostic Accuracy of Ultrasonography and Magnetic Resonance Imaging for FIGO Grading of Placenta Accreta Spectrum: A Histopathology-Based Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-20 08:41:16","doi":"10.21203/rs.3.rs-8634583/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":"f3efd571-c426-4d89-a8c4-0b92c91c5584","owner":[],"postedDate":"January 20th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":61332593,"name":"Obstetrics \u0026 Gynecology"}],"tags":[],"updatedAt":"2026-01-20T08:41:16+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-20 08:41:16","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8634583","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8634583","identity":"rs-8634583","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}