Prenatal planning of placenta previa: diagnostic accuracy of a novel MRI-based prediction model for placenta accreta spectrum (PAS) and clinical outcome

• Published in: Abdominal imaging Vol. 44; no. 5; pp. 1873 - 1882
• Main Authors: Delli Pizzi, Andrea, Tavoletta, Alessandra, Narciso, Roberta, Mastrodicasa, Domenico, Trebeschi, Stefano, Celentano, Claudio, Mastracchio, Jacopo, Cianci, Roberta, Seccia, Barbara, Marrone, Luisa, Liberati, Marco, Cotroneo, Antonio Raffaele, Caulo, Massimo, Basilico, Raffaella
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2019; Springer Nature B.V
• Subjects: Accuracy; Bleeding; Childbirth & labor; Clinical outcomes; DIAGNOSIS; Diagnostic systems; FORECASTING; Function analysis; Gastroenterology; Hepatology; Hysterectomy; Imaging; Magnetic resonance imaging; Mathematical models; Medical diagnosis; Medicine; Medicine & Public Health; Model accuracy; Myometrium; NMR IMAGING; PATHOLOGY; Pelvis; PLACENTA; PLANNING; Prediction models; Pregnancy complications; Radiology; RADIOLOGY AND NUCLEAR MEDICINE; Sensitivity; Thinning; Uterus; Clinical outcome; Placenta previa; Placental invasion; Intrapartum bleeding; Placenta accreta spectrum (PAS); Magnetic resonance
• ISSN: 2366-004X; 2366-0058; 2366-0058
• DOI: 10.1007/s00261-018-1882-8

Purpose To investigate the diagnostic accuracy of MRI for placenta accreta spectrum (PAS) and clinical outcome prediction in women with placenta previa, using a novel MRI-based predictive model. Methods Thirty-eight placental MRI exams performed on a 1.5T scanner were retrospectively reviewed by two radiologists in consensus. The presence of T2 dark bands, myometrial thinning, abnormal vascularity, uterine bulging, placental heterogeneity, placental protrusion sign, placental recess, and percretism signs was scored using a 5-point scale. Pathology and clinical intrapartum findings were the standard of reference for PAS, while intrapartum/peripartum bleeding and emergency hysterectomy defined the clinical outcome. Receiver-operating characteristic (ROC) analysis and discriminant function analysis were performed to test the predictive power of MRI findings for both PAS and clinical outcome prediction. Results Abnormal vascularity and percretism signs were the two most predictive MRI features of PAS. The area under the curve (AUC) of the predictive function was 0.833 (cutoff 0.39, 67% sensitivity, 100% specificity, p  = 0.001). Percretism signs and myometrial thinning were the two most predictive MRI features of poor outcome. AUC of the predictive function was 0.971 (cutoff − 0.55, 100% sensitivity, 77% specificity, p  < 0.001). Conclusion The diagnostic accuracy of MRI, especially considering the combination of the most predictive MRI findings, is higher when the target of the prediction is the clinical outcome rather than the PAS.