Cine magnetic resonance imaging of the uterus for evaluation of abnormal uterine bleeding

Abstract

To assess the potential role of cine magnetic resonance imaging (MRI) in the evaluation of uterine peristalsis in women classified with abnormal uterine bleeding - endometrial (AUB-E) by measuring frequency and directionality of waveforms. This was a prospective pilot study of seven women with normal menses and eight women with AUB-E, defined as regular but excessive flow causing anemia or interfering with daily activities. Exclusion criteria included other causes of AUB in the PALM-COEIN system. Subjects were evaluated using a modified Menstrual Impact Questionnaire (MIQ). MRI studies were performed within days 1-5 of the subject's menstrual cycle using a 3.0T MRI and 8-channel cardiac phased array coil. Axial and sagittal T2-weighted fast spin echo was obtained to evaluate uterine morphology. Cine MRI imaging was performed using a single shot fast spin echo with a temporal resolution of 2 to 3 seconds over a 2 minutes sequence to evaluate frequency and directionality of uterine waveforms, repeated 2-3 times, and maximum number of waveforms per two minutes reported. Images were reviewed independently by two expert radiologists blinded to patients’ histories. Primary outcome was peristaltic frequency of the subendometrium measured as number of waveforms per two minutes. Secondary outcome was directionality. Primary outcome and MRI morphology were compared by Mann-Whitney U test. MIQ responses were compared by Fischer’s exact test and Mann-Whitney U test. Normal subjects bled an average of 3.9 days and those with AUB-E bled an average of 6.4 days (p= 0.016). Normal subjects defined their flow as light or moderate. Six of seven normal subjects reported no impact on their work, physical or social activity. In comparison, all but one subject with AUB-E defined their flow as heavy or very heavy with passage of clots or flooding (p = 0.001). All subjects with AUB-E reported effect on their daily activities (p < 0.001) and were more likely to report effect on their social activity (p < 0.001) and physical activity (p < 0.001). Subjects with AUB-E were more likely to report dysmenorrhea (p=0.041). Thirteen of fifteen women demonstrated motility of the subendometrium during cine display. Two women with AUB-E did not demonstrate waveforms. There was complete agreement between readers with regard to maximum number of waveforms per two minute cycle and directionality. Median number of waveforms in subjects with normal menses was 3 per two minutes. In patients with AUB-E, the median number of waveforms was 1 per two minutes (p=0.009). All subjects with waveforms exhibited cervico-fundal directionality during menses. Cine MRI is a feasible modality for measuring differences in the frequency of uterine peristalsis in women with AUB-E. This pilot study supports further investigation into the endometrial and myometrial contributions to abnormal bleeding in women with AUB-E.