Uterine arterial embolization for leiomyomas: perfusion and volume changes at MR imaging and relation to clinical outcome.

PURPOSE: To monitor changes in perfusion and volume of uterus and leiomyomas after bilateral uterine artery embolization (UAE) and to correlate immediate perfusion changes with subsequent reduction in leiomyoma volume and clinical outcome.
MATERIALS AND METHODS: Eleven consecutive women underwent magnetic resonance (MR) imaging before UAE, immediately after, and at 1 and 4 months. Reduction in maximal enhancement above baseline at 90 seconds (ME(90)) after injection of the dominant leiomyoma immediately after embolization was correlated with its volume reduction at 4 months and with clinical response at 12 months.
RESULTS: Forty-five leiomyomas were noted (mean, four per patient). Myometrium enhanced briskly (ME(90) of 110%), with a reduction in ME(90) to 26% immediately after embolization. Initial leiomyoma ME(90) was lower (P <.001), but it suppressed to baseline levels immediately after embolization. At 1 and 4 months, myometrial perfusion returned to normal, but leiomyoma perfusion remained suppressed (P <.001). Immediate reduction in leiomyoma ME(90) correlated with clinical response (Spearman rho = 0.64). Leiomyomas initially high in SI on T2-weighted images showed significantly greater volume reduction than those low in SI (P =.006). Well-perfused leiomyomas did not show greater volume reduction than those that were poorly perfused. Volume reduction did not correlate with improvement in clinical symptom score.
CONCLUSION: Immediate reduction in leiomyoma perfusion after bilateral UAE correlates with clinical response, whereas leiomyomas initially high in SI on T2-weighted images indicate a likely greater volume reduction.