Martin Thomas, Janzen Carla, Li Xinzhou, Del Rosario Irish, Chanlaw Teresa, Choi Sarah, Armstrong Tess, Masamed Rinat, Wu Holden H, Devaskar Sherin U, Sung Kyunghyun
Radiological Sciences, University of California Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Department of Obstetrics and Gynecology, University of California Los Angeles (UCLA), Los Angeles, CA 90095, USA.
Diagnostics (Basel). 2020 Oct 19;10(10):840. doi: 10.3390/diagnostics10100840.
Magnetic resonance imaging (MRI) is a promising non-invasive imaging technique that can be safely used to study placental development and function. However, studies of the human placenta performed by MRI are limited by uterine motion and motion in the uterus during MRI remains one of the major limiting factors. Here, we aimed to investigate the characterization of uterine activity during MRI in the second trimester of pregnancy using MRI-based motion tracking. In total, 46 pregnant women were scanned twice (first scan between 14 and 18 weeks and second scan between 19 and 24 weeks), and 20 pregnant subjects underwent a single MRI between 14 and 18 weeks GA, resulting in 112 MRI scans. An MRI-based algorithm was used to track uterine motion in the superior-inferior and left-right directions. Uterine contraction and maternal motion cases were separated by the experts, and unpaired Wilcoxon tests were performed within the groups of gestational age (GA), fetal sex, and placental location in terms of the overall intensity measures of the uterine activity. In total, 22.3% of cases had uterine contraction during MRI, which increased from 18.6% at 14-18 weeks to 26.4% at 19-24 weeks GA. The dominant direction of the uterine contraction and maternal motion was the superior to the inferior direction during early gestation.
磁共振成像（MRI）是一种很有前景的非侵入性成像技术，可安全用于研究胎盘发育和功能。然而，通过MRI对人体胎盘进行的研究受到子宫运动的限制，并且在MRI过程中子宫内的运动仍然是主要限制因素之一。在此，我们旨在使用基于MRI的运动跟踪技术研究妊娠中期MRI期间子宫活动的特征。总共对46名孕妇进行了两次扫描（第一次扫描在14至18周之间，第二次扫描在19至24周之间），并且20名孕妇在妊娠14至18周之间接受了一次MRI扫描，共获得112次MRI扫描。使用基于MRI的算法在上下和左右方向上跟踪子宫运动。专家将子宫收缩和母体运动情况进行了区分，并就子宫活动的总体强度测量，在胎龄（GA）、胎儿性别和胎盘位置组内进行了非配对Wilcoxon检验。总共，22.3%的病例在MRI期间出现子宫收缩，这一比例从14至18周时的18.6%增加到妊娠19至24周时的26.4%。在妊娠早期，子宫收缩和母体运动的主导方向是从上到下。
