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

Abstract

Aim: To determine the optimal repetition time (TR) of cine imaging for uterine peristalsis on 3 T magnetic resonance imaging (MRI).

Materials and methods: 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 (Cine_2s) and 4 seconds (Cine_4s) 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.

Results: The SNR_endometrium (263.14±91.54) and CNR_{endometrium -junction zone} (134.30±46.91) in Cine_4s were significantly higher than those in Cine_2s (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 Cine_2s (7.13±1.58) was significantly higher than that in Cine_4s (5.30±1.06). Cine_2s could identify peristaltic directions more clearly than Cine_4s; however, no significant difference was observed in the intensity of uterine peristalsis between Cine_2s and Cine_4s (p=0.509).

Conclusion: At 3 T MRI, the number and direction of endometrium peristalsis could was displayed better using Cine_2s than Cine_4s, with the uncompromised image quality.