MRI of uterine fibroleiomyoma before and after embolization of uterine arteries

Objective To evaluate the MRI appearances of uterine fibroleiomyomas before and after uterine arterial embolization (UAE).Methods MRI was performed in 34 patients(62 fibroleiomyomas)before and 4 months after embolization of the uterine arteries.The signal intensity and gadolinium enhancement characteristics of fibroleiomyomas were assessed in comparison with those of skeletal muscle.The volume of the lesion was measured by using the ellipsoid formula.Results The mean lesions volume was 85.6cm3 (0.3-248.4 cm3) before embolization and 32.6 cm3 (0.3-65.4 cm3) after UAE.The mean reduction in lesions volume was 58.32% at 4 months.The reduction in 40 lesions whose volume was over 35 cm3 before UAE was 62.48%,while the reduction in 22 lesions whose volume was less than 35 cm3 before UAE was 38.69%.Before UAE,all fibroleiomyomas presented as intermediate or low signal intensity on T 1WI,low or heterogeneous signal intensity on T 2WI.After UAE,38 lesions showed homogeneous low signal, 20 showed iso-signal and 4 showed slightly high signal on T 1WI while all cases were extremely low signal on T 2WI except 7 were slightly low.On dynamic and delayed contrast enhanced images,40 lesions whose volume was over 35 cm3 before UAE remained no enhancement except 2,but 22 lesions whose volume was less than 35 cm3 before UAE enhanced heterogeneously with a different degree except 5.The normal myometrium after UAE enhanced obviously just as that before treatment.Conclusion MRI was useful for the evaluation of the volume changes and the blood supply in fibroleiomyomas before and after UAE.