UTERINE CONTRACTIONS - POSSIBLE DIAGNOSTIC PITFALL AT MR-IMAGING

A total of 206 nongravid patients with various gynecologic problems un derwent pelvic magnetic resonance (MR) examinations that included both sagittal T2-weighted and contrast agent-enhanced T1-weighted images. MR images were retrospectively reviewed to identify changes in endomet rial configuration on serial images obtained during the same MR examin ation. In 20 MR examinations (all in women of reproductive age), endom etrial distortion due to myometrial bulging was noted on T2-weighted o r contrast-enhanced T1-weighted images. It was absent on other MR imag es obtained at different times. Myometrial bulging exhibited low signa l intensity in 18 examinations. The finding resembled adenomyosis or l eiomyoma on T2-weighted or contrast-enhanced T1-weighted images. These results evidence the presence of transient myometrial bulging and tra nsient low-intensity myometrium in the nongravid uterus. This phenomen on is thought to represent uterine contraction. Clinicians should be a ware of the potential presence of transient low-signal-intensity myome trial bulging that could present diagnostic problems in the normal ute rus.