title: Postpartum MR diagnosis of retained placenta accreta.
abstract: Retained placenta accreta can cause catastrophic postpartum hemorrhage. This study aims to determine whether MR imaging can differentiate retained placenta accreta from postpartum hemorrhage caused by other conditions. Fourteen cases suspicious for retained placenta were examined with MR imaging. Signal intensity, the enhancing pattern of uterine contents, and flow voids within the myometrium were retrospectively studied. As hysterectomy was performed in only two cases, final diagnosis was based on clinical outcome and analysis of uterine contents. Final diagnoses were retained placenta accreta in seven cases, retained normally attached placenta in four, hematoma in two, and placental site trophoblastic tumor (PSTT) in one. All seven cases with placenta accreta had a very hyperintense area on T2-weighted images, showing transient early enhancement. None demonstrated delayed strong enhancement around the hyperintense area. In two cases with retained normally attached placenta and in both with hematomas, there were no hyperintense areas on T2-weighted images. Of these, only one showed transient early enhancement. Flow voids were observed in four cases with placenta accreta, one with normally attached placenta, and the case with PSTT. A markedly hyperintense area on T2-weighted images and transient early enhancement without delayed strong enhancement between the mass and the myometrium can indicate retained placenta accreta.
authors.affiliation: Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan. ytanaka@md.tsukuba.ac.jp
authors.forename: Yumiko Oishi
authors.initials: YO
authors.lastname: Tanaka
authors.forename: Sadahiko
authors.initials: S
authors.lastname: Shigemitsu
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Ichikawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sohda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Yuji
authors.initials: Y
authors.lastname: Itai
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008279:Magnetic Resonance Imaging; D010920:Placenta / Q000473:pathology; D010921:Placenta Accreta / Q000175:diagnosis*; D006473:Postpartum Hemorrhage / Q000175:diagnosis; D011247:Pregnancy