Predictive value of magnetic resonance imaging signal and contrast-enhancement characteristics on post-embolization volume reduction of uterine fibroids

Purpose: To assess the magnetic resonance imaging (MRI) signal and contrast-enhancement features of uterine fibroids before and after embolization, and to determine whether or not there are pre-embolization MRI characteristics that predict the volume reduction of fibroids. Material and Methods: Uterine fibroid embolization (UFE) was carried out in 28 fibroids of 20 patients, all of whom were symptomatic. The patients were prospectively evaluated with T1-weighted, T2-weighted, and gadolinium-enhanced T1 MRI sequences before and 6 months after embolization. The relationship between the characteristics of MRI signal and contrast-enhancement features of fibroids before the procedure and the change in size of the lesions after treatment was investigated. Results: Before embolization, the mean volume of fibroids was 123 cm(3) (8-560 cm(3)). The decrease rate in fibroid volumes was 44.6% (range 7-70%) 6 months after embolization. Volume reduction was more prominent in fibroids that had a high signal intensity on T2-weighted images and a marked contrast enhancement on T1-weighted images (P < 0.001). However, the volume reduction was insufficient in fibroids with high signal characteristics on pre-contrast T1-weighted images (P < 0.001). Conclusion: MRI is an effective method for revealing size and signal changes of fibroids after embolization. MRI signal characteristics and the contrast-enhancement pattern of fibroids before embolization can predict tumor volume reduction after embolization.