Retained placental tissue: role of MRI findings in diagnosis and clinical assessment

Abstract

Objective: To assess the role of MRI in diagnosis and predicting clinical outcome in women with retained placental tissue.

Patients and methods: Eleven patients with pathologically proven RPT were retrospectively studied. All underwent MRI. The following MRI parameters of RPT were studied: size, signal intensity on T1- and T2-weighted images, enhancement pattern on dynamic study, extent of attachment to the uterine myometrium, and myometrial thickness at the attachment site. Clinical reports were reviewed and MRI findings were compared with respect to outcome.

Results: RPT diameter varied from 30 to 102 mm. On T2-weighted images, 10 cases showed high intensity, while on T1-weighted images, seven cases showed high intensity. Nine cases were hypervascular. The myometrium was thinner at the attachment side than at the opposite side. All five cases in which RPT was delivered spontaneously showed an attachment area of less than a semicircle, hence broad attachment appears to impede detachment and necessitate additional therapy. After uterine arterial embolization, two patients showed complete infarction of RPT on enhanced MRI.

Conclusion: MRI is useful for diagnosis and follow-up of RPT. The evaluation of extent of RPT attachment to the myometrium and vascularity on MRI can help the clinical assessment.