The assessment of myometrium perfusion in patients with uterine fibroid by arterial spin labeling MRI

BACKGROUND It has been suggested that an inadequate blood supply caused by uterine fibroids may lead to decreasing fertility. Therefore, a quantitative evaluation of blood flow in the uterus might be a good tool for infertility treatments. For the first step, the ability to perform arterial spin labeling (ASL)-MRI in pelvic organs was examined by measuring blood flow in the uterine muscle layer. RESULTS Three normal volunteer women, seven patients with one uterine fibroid and four patients treated with GnRH analogue for uterine fibroids, were enrolled in this study. Perfusion of normal uterine myometrium was examined using non-enhanced ASL-MRI. The region of interest was set in the uterine muscle layer, with a point in the iliopsoas or gluteus muscle. The ASL perfusion index was calculated as (ASL value in uterus-ASL value in iliopsoas/gluteus muscle). The ASL perfusion indexes in the secretory phase of all 3 volunteers were significantly lower than the indexes in the proliferative phases (P < 0.05). In patients with fibroids, all three types of fibroids (subserosal, intramural and submucosal types) were included. In seven patients harboring a single uterine fibroid, the ASL perfusion indexes of myometrium on the fibroid-positive side increased 4.9 fold compared with that of the fibroid-negative side. With GnRH analogue treatment, ASL perfusion in myometrium decreased to 39% on average (P < 0.05). CONCLUSION We utilized the ASL-MRI technique to evaluate perfusion of uterine myometrium. For clinical use, an inadequate blood supply caused by uterine fibroids is known to lead to decreasing fertility. The ASL-MRI technique might be useful to evaluate blood supply as a quantitative measurement of fertility in patients with uterine fibroids.