To evaluate whether functional MR can assist in characterizing fibroids at greater likelihood of significant volume reduction, we examined whether there is a correlation between fibroid apparent diffusion coefficient (ADC) prior to embolization and fibroid volume reduction following UFE.
Materials & Methods
Patients were included in this study if they had an MRI prior to and following UAE (> 100 days). All fibroids greater than 3 cm were included, with up to 4 fibroids per patient. Fibroid volumes were measured on pre and post procedural T2 weighted TSE MR images and percent volume reduction was calculated. Diffusion weighted images (DWI) were obtained using a single shot EPI sequence with b values of 0, 500 and 1000 sec/mm2. Fibroid ADC were calculated based on the b=500 and b=1000 images. A Pearson correlation test was performed to calculate the linear relationship between fibroid ADC and volume reduction.
Results
8 patients (average age 42 y) with 21 fibroids were analyzed. Fibroid volumes ranged from 16 to 430 cm3. Mean fibroid volume reduction after embolization (range, 152 - 316 days) with trisacryl gelatin microspheres was 55% (range 13-100%). The mean pre embolization fibroid ADC was 0.72 mm2/sec (range 0.36 to 1.20). The Pearson correlation coefficient was 0.58. 100% (7/7) of fibroids with ADC > 0.75 mm2/sec decreased in volume by greater than 50%. 29% (4/14) of fibroids with ADC < 0.75 mm2/sec decreased in volume by greater than 50%.
Conclusion
Functional MRI of fibroids prior to uterine artery embolization may help predict volumetric reduction with the use of high b-value apparent diffusion coefficient, and potentially assist in identifying patients with bulk-related symptoms who are best suited to UFE. Further prospective evaluation within a larger patient cohort is required.
New York University School of Medicine, New York, NY
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