Evaluation of the routine use of pelvic MRI in women presenting with symptomatic uterine fibroids: When is pelvic MRI useful?

Background: Pelvic ultrasound (US) diagnosis of uterine fibroids may overlook coexisting gynecological conditions that contribute to women's symptoms.

Purpose: To determine the added value of pelvic MRI for women diagnosed with symptomatic fibroids by US, and to identify clinical factors associated with additional MRI findings.

Study Type: Retrospective observational study.

Population: In all, 367 consecutive women with fibroids diagnosed by US and referred to our multidisciplinary fibroid center between 2013-2017.

Field Strength/sequence: All patients had both pelvic US and MRI prior to their consultations. MRIs were performed at 1.5 T or 3 T and included multiplanar T -weighted sequences, and precontrast and postcontrast T -weighted imaging.

Assessment: Demographics, symptoms, uterine fibroid symptom severity scores, and health-related quality of life scores, as well as imaging findings were evaluated.

Statistical Tests: Patients were separated into two subgroups according to whether MRI provided additional findings to the initial US. Univariate and multivariate regression analyses were performed.

Results: Pelvic MRI provided additional information in 162 patients (44%; 95% confidence interval [CI] 39-49%). The most common significant findings were adenomyosis (22%), endometriosis (17%), and partially endocavitary fibroids (15%). Women with pelvic pain, health-related quality of life scores less than 30 out of 100, or multiple fibroids visualized on US had greater odds of additional MRI findings (odds ratio [OR] 1.68, 2.26, 1.63; P = 0.02, 0.004, 0.03, respectively), while nulliparous women had reduced odds (OR 0.55, P = 0.01). Patients with additional MRI findings were treated less often with uterine fibroid embolization (14% vs. 36%, P < 0.001) or MR-guided focused US (1% vs. 5%, P = 0.04), and more often with medical management (17% vs. 8%, P = 0.01).

Data Conclusion: Pelvic MRI revealed additional findings in more than 40% of women presenting with symptoms initially ascribed to fibroids by US. Further evaluation using MRI is particularly useful for parous women with pelvic pain, poor quality of life scores, and/or multiple fibroids.

Level Of Evidence: 4 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019.