An optimised repetition time (TR) for cine imaging of uterine peristalsis on 3 T MRI

Abstract

To determine the optimal repetition time (TR) of cine imaging for uterine peristalsis on 3 T magnetic resonance imaging (MRI). Twenty-three young female volunteers (age range: 23-28 years, mean: 24.91±1.12 years) underwent 3 T MRI for uterine peristalsis in the periovulatory phase. A midsagittal section of their uteri was scanned using a single-shot fast spin echo sequence with TR of 2 seconds (Cine2s) and 4 seconds (Cine4s) for 3 minutes. Subjective image-quality scores, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs) of these MRI images were evaluated by two radiologists independently. The number, direction, and intensity of uterine peristalsis in the MRI images with two TRs were compared at 15 times the actual speed. The SNRendometrium (263.14±91.54) and CNRendometrium -junction zone (134.30±46.91) in Cine4s were significantly higher than those in Cine2s (209.01±96.53, 104.05±50.19; p=0.042, 0.015, respectively); however, no significant differences were found in other objective indexes and subjective image quality score (p>0.05). In addition, the peristaltic number of Cine2s (7.13±1.58) was significantly higher than that in Cine4s (5.30±1.06). Cine2s could identify peristaltic directions more clearly than Cine4s; however, no significant difference was observed in the intensity of uterine peristalsis between Cine2s and Cine4s (p=0.509). At 3 T MRI, the number and direction of endometrium peristalsis could was displayed better using Cine2s than Cine4s, with the uncompromised image quality.