Hyperintense uterine leiomyoma at T2-weighted MR imaging: differentiation with dynamic enhanced MR imaging and clinical implications.

Abstract

PURPOSE: To evaluate the role of dynamic enhanced magnetic resonance (MR) imaging in differentiating leiomyomas with high signal intensity at T2-weighted imaging. MATERIALS AND METHODS: Histologic features of 34 uterine leiomyomas that showed hyperintensity on T2-weighted images were compared with those of ordinary hypointense leiomyomas (n = 74). The results of treatment with gonadotropin-releasing hormone analogue were also analyzed in relation to pretreatment signal intensity. RESULTS: Degenerated leiomyomas (n = 13) had higher signal intensity and heterogeneous architecture, but there was considerable overlap in signal intensity with cellular leiomyomas (n = 21). At dynamic enhanced MR imaging, cellular leiomyomas had marked contrast enhancement in the early phase, while degenerated leiomyomas showed slight or irregular enhancement. Cellular leiomyomas were reduced significantly in size after treatment (P = .02). The response in degenerated leiomyomas was minimal. CONCLUSION: Evaluation of signal intensity at T2-weighted imaging and degree of contrast enhancement at dynamic enhanced MR imaging provide useful information on the nature of leiomyomas.