Diagnostic Value of Combined MRI and Ultrasound Features in Invasive Placenta Accreta and Prediction of Adverse Outcomes

Deng Ying Li,1 Zong Fang Sun,2 Qing Lu3 1First People’s Hospital of Linping District, Hangzhou, Zhejiang Province, 311100, People’s Republic of China; 2Pingyi County Hospital of Traditional Chinese Medicine, Linyi City, Shandong, 273300, People’s Republic of China; 3Obstetrics Department, Jinan Maternal and Child Health Hospital, Jinan, Shandong, 250001, People’s Republic of ChinaCorrespondence: Qing Lu, Obstetrics Department, Jinan Maternal and Child Health Hospital, No. 2 Jianguo Xiaojing Sanlu, Shizhong District, Jinan City, Shandong Province, 250001, People’s Republic of China, Email [email protected]: This study aimed to evaluate the diagnostic value of magnetic resonance imaging (MRI) combined with ultrasound features in invasive placenta accreta and to assess their effectiveness in predicting adverse clinical outcomes.Methods: A retrospective analysis was conducted on 173 pregnant women with suspected placenta accreta who were admitted to our hospital between March 2022 and May 2024. Surgical or pathological findings served as the diagnostic criteria. Patients were divided into an invasive placenta accreta group (n=104; including accreta and percreta) and a non-invasive group (n=69; including no placenta accreta or placenta adherent types). Baseline characteristics, MRI, and ultrasound features were compared between groups. Logistic regression was used to identify independent risk factors, and receiver operating characteristic (ROC) curves were applied to evaluate the diagnostic performance of MRI, ultrasound, and their combination. The invasive placenta accreta group was further classified into an adverse outcome subgroup (n=48; defined as intraoperative blood loss ≥ 1500 mL and/or hysterectomy) and a good outcome subgroup (n=56). The diagnostic value of imaging features for predicting adverse outcomes was analyzed.Results: Independent risk factors for invasive placenta accreta included myometrial thinning, low placental T2WI signal, blurred uteroplacental interface, abnormal placental vascular proliferation, localized bulging, loss of retroplacental space, moth-eaten placental changes, disrupted blood flow at the placental base, and ultrasound score (all P< 0.05). The combined diagnosis achieved the highest diagnostic performance, with an AUC of 0.932 (95% CI: 0.876– 0.965), sensitivity of 96.53%, and specificity of 91.91%, outperforming individual features. For predicting adverse outcomes, the combined model also demonstrated excellent accuracy, with an AUC of 0.941 (95% CI: 0.868– 0.974), sensitivity of 93.06%, and specificity of 94.22%.Conclusion: MRI and ultrasound imaging features can be used independently or jointly in diagnosing invasive placenta accreta and predicting related adverse outcomes. The combined approach provides significantly better diagnostic accuracy and clinical value than either modality alone.Keywords: magnetic resonance imaging, ultrasound, combined diagnosis, invasive placenta accreta, adverse outcomes, predictive value