Role of MR imaging of uterine leiomyomas before and after embolization.

Leiomyoma, the most common uterine neoplasm, is composed of smooth muscle with varying amounts of fibrous connective tissue. Most leiomyomas are asymptomatic, but patients may present with abnormal uterine bleeding or bulk-related symptoms. Over the past decade, uterine fibroid embolization (UFE) has been an effective minimally invasive treatment for symptomatic patients. Magnetic resonance (MR) imaging is the most accurate imaging technique for detection and evaluation of leiomyomas and therefore has become the imaging modality of choice before and after UFE. As leiomyomas enlarge, they may outgrow their blood supply, resulting in various forms of degeneration that change their appearance. Leiomyomas are classified as submucosal, intramural, or subserosal. Submucosal and subserosal leiomyomas may be pedunculated, thus simulating other conditions. Understanding the MR imaging appearance of leiomyomas allows differentiation from other entities. The superior tissue contrast of MR imaging allows diagnosis of leiomyomas with a high level of confidence, ultimately leading to a decrease in the number of surgeries performed and thus reducing healthcare expenditures. MR imaging findings that influence the planning of UFE include the location, size, number, and vascular supply of leiomyomas. In addition, MR imaging can be used to assess the success of UFE and evaluate for potential complications. © RSNA, 2012.