Comparison of 1.5 T and 3 T non-contrast-enhanced MR angiography for visualization of uterine and ovarian arteries before uterine artery embolization

Objectives This study aimed to compare the performance of non-contrast-enhanced magnetic resonance angiography (NCE-MRA) at 1.5 T and 3 T for the visualization of uterine and ovarian arteries (OAs) before uterine artery embolization (UAE). Methods Preprocedural pelvic NCE-MRA images of 85 symptomatic patients undergoing UAE for the treatment of uterine leiomyomas were reviewed by two specialists in pelvic MRI. Left and right uterine arteries (UAs) were judged separately and scored on a 5-point scale. Score 5 was the highest, in which the UA could be visualized inside the musculature, forming a peritumoral plexus. Score 1 was the lowest, where visualization was limited to the descending segment. The detection of enlarged OAs was also compared. The Mann-Whitney U and Fisher exact tests were used for statistical analysis. p < 0.05 was considered to be statistically significant. Results Of the 170 UAs, 110 were classified at 1.5 T and 60 were classified at 3 T. Median (interquartile range [IQR]) score was 3 (IQR: 2-4) for visualization at 1.5 T vs 5 (IQR: 4-5) for 3 T. The scores for UA visualization were significantly higher at 3 T (p < 0.05). For enlarged OAs, NCE-MRA at 1.5 T and 3 T visualized 7 and 5 enlarged OAs, respectively; there was no significant difference between the two field strengths (p = 0.36). Conclusions NCE-MRA performed at 3 T can visualize UAs over a greater range than at 1.5 T. No difference was found regarding the detection of enlarged OAs.