Enhanced Myometrial Vascularity and High-Flow Vascular Lesions of the Postpregnancy Uterus: Imaging Features and Clinical Significance

The diagnosis and management of vascular abnormalities of the postpregnancy uterus are often challenging due to overlapping clinical and imaging features of the various entities discussed in this article. Both acquired vascular lesions with highflow arteriovenous (AV) shunting and pregnancy-related physiologic alterations in uterine vasculature can cause abnormal vaginal bleeding. In recent years, there has been increasing awareness of the potential for overdiagnosis of high-flow uterine vascular lesions that resemble AV malformations (AVMs) after recent intrauterine pregnancy, potentially resulting in suboptimal patient management. Overdiagnosis of AVMs can result in unnecessary procedures, such as uterine artery embolization, or withholding of dilation and curettage when retained products of conception are present, resulting in persistent bleeding and infection. Enhanced myometrial vascularity (EMV) refers to a tortuous, rich vascular network found within the myometrium and extending into the endometrium that is observed after recent intrauterine pregnancy and is a frequent imaging finding in patients with bleeding in this setting. This Pictorial Essay focuses on the pathophysiology, clinical presentation, and imaging features of EMV and differentiation of this often transient phenomenon from highflow vascular lesions of the uterus, such as AVMs and AV fistulas. Treatment strategies and the role of imaging in guiding patient management are discussed along with the controversy surrounding the terminology used to describe uterine hypervascular lesions after recent pregnancy.