Comparing magnetic resonance imaging and ultrasound in the clinical evaluation of fibroids prior to uterine artery embolization

Purpose: Uterine artery embolization has become established as a frontline treatment for uterine leiomyomata. In planning embolization, preprocedural imaging can further characterize pathology and anatomy, but it may also reveal coexisting diagnoses that have the potential to change clinical management. The purpose of this study is to compare the diagnostic outcomes of ultrasound and MRI performed for patients prior to undergoing embolization. Methods: The study cohort consisted of 199 patients who underwent uterine artery embolization at a single academic institution between 2013 and 2018. Prior to embolization, all patients had an MRI confirming a leiomyomata diagnosis. Additionally, 118 patients underwent transvaginal ultrasound within five years prior to MRI. MRI findings were analyzed and, when applicable, compared to prior ultrasound impressions to assess for the incidence of new findings. The diagnoses of interest were adenomyosis, hydrosalpinx, predominantly infarcted leiomyomata, and large intracavitary leiomyomata. Data were collected from retrospective chart review and included demographics, symptomology, and imaging reports. Results: 199 patients ultimately underwent embolization for treatment of MRI-confirmed leiomyomata. Of 118 patients who also had an ultrasound within five years prior to their MRI, 26 (22.0%) received a second gynecologic diagnosis based on MRI findings that was not previously seen on ultrasound. Of 81 patients who only had an MRI before embolization, 19 (23.5%) received a second gynecologic diagnosis not previously documented. The most common coexisting pathology was adenomyosis, presenting in 34 (17.1%) patients with leiomyomata, followed by large intracavitary leiomyomata (8, 4.0%), infarcted leiomyomata (7, 3.5%), and hydrosalpinx (6, 3.0%),. Conclusions: When considering uterine artery embolization for the treatment of symptomatic leiomyomata, preprocedural MRI is superior to ultrasound in detecting coexisting pathologies, including adenomyosis and hydrosalpinx. It can also better characterize leiomyomata, including identifying lesions as intracavitary or infarcted. These findings have the potential to alter clinical management or contraindicate embolization entirely.