Department of Radiology and Fetal Medicine Institute, Children's National Medical Center, 111 Michigan Ave., Washington, DC, 20010, USA.
, St. Petersburg, FL, USA.
Pediatr Radiol. 2021 Jul;51(8):1332-1338. doi: 10.1007/s00247-021-04969-1. Epub 2021 Feb 20.
Malrotation of the bowel refers to any variation in the rotation and fixation of the gastrointestinal tract during the first trimester and is most commonly detected postnatally. Nonrotation of the bowel and incomplete rotation of the bowel are subtypes of malrotation.
To determine if the nonrotation subtype of malrotation of the bowel can be detected on prenatal magnetic resonance imaging (MRI).
Cases from 2012 to 2018 with nonrotation of the bowel without obstruction confirmed by imaging, surgery and/or autopsy were compared to prenatal imaging. Prenatal imaging was retrospectively reviewed to determine if prenatal diagnosis of malrotation could be made. Exclusion criteria included diaphragmatic hernia, omphalocele and gastroschisis.
Ten cases of nonrotation diagnosed postnatally by upper gastrointestinal series (upper GI)/small bowel follow-through (SBFT) or autopsy had prenatal MRI. Prenatal MR studies were performed for assessment of heterotaxy syndrome with congenital heart disease (6/10), congenital heart disease with additional anomalies (suspected VACTERL [vertebral, anorectal, cardiac, tracheoesophageal, renal, limb] and suspected lung agenesis, ventriculomegaly) (3/10) and skeletal dysplasia (1/10). Eight upper GI/SBFT cases demonstrated nonrotation of the bowel without obstruction with the small bowel completely on one side of the abdomen contralateral to the stomach and the colon ipsilateral to the stomach; four cases were confirmed by surgery. The small bowel in one upper GI/SBFT case was unilateral contralateral to the stomach with a meandering colon. One case had nonrotation diagnosed at autopsy. There were no cases of postnatal midgut volvulus. Retrospective review of the 10 cases had prenatal MRI performed between 23 and 37 weeks of gestation. The coronal plane was the most optimal plane to assess the position of the stomach, small bowel and colon in relationship to each other. The small bowel was best assessed on T2-weighted images while the colon was best assessed on T1-weighted images. A nonrotated position of the small bowel was present in all 10 fetal MRI cases mirroring postnatal findings, with the small bowel contralateral to the stomach in 9/10 cases and ipsilateral to the stomach (in the right abdomen) in 1/10 cases. The colon was visualized by prenatal MRI in 9/10 cases, with 1 case limited due to a lack of T1-weighted imaging. A nonrotated position of the colon contralateral to the small bowel was present in 7/9 cases. In 2/9 cases, the colon was wandering, positioned on both sides of the midline. Colonic position in all nine cases matched postnatal findings. No cases presented with prenatal bowel obstruction.
Detection of nonrotation of the bowel is possible on prenatal MRI.
肠旋转不良是指在第一孕期胃肠道旋转和固定的任何变化，最常见于产后发现。肠旋转不良的亚型包括肠不旋转和肠不完全旋转。
确定产前磁共振成像（MRI）是否可以检测到肠旋转不良的不旋转亚型。
对 2012 年至 2018 年期间因影像学、手术和/或尸检证实无梗阻的肠不旋转病例进行研究，并与产前影像学进行比较。回顾性分析产前影像学资料，以确定是否可以做出产前肠旋转不良的诊断。排除标准包括膈疝、脐膨出和腹裂。
10 例经上消化道造影（UGI）/小肠造影（SBFT）或尸检诊断为不旋转的病例进行了产前 MRI。产前 MR 研究用于评估伴有先天性心脏病的异构综合征（6/10）、伴有其他异常的先天性心脏病（疑似 VACTERL[椎体、肛门直肠、心脏、气管食管、肾脏、肢体]和疑似肺发育不全、脑室扩大]）（3/10）和骨骼发育不良（1/10）。8 例 UGI/SBFT 病例显示肠不旋转且无梗阻，小肠完全位于腹部对侧与胃相对的一侧，大肠与胃同侧；4 例经手术证实。1 例 UGI/SBFT 病例的小肠单侧位于胃对侧，结肠呈蜿蜒状。1 例病例经尸检诊断为不旋转。无产后中肠扭转病例。10 例病例的回顾性分析显示，产前 MRI 检查在 23 至 37 周妊娠之间进行。冠状面是评估胃、小肠和大肠相互位置的最佳平面。在 T2 加权图像上最好评估小肠，在 T1 加权图像上最好评估大肠。10 例胎儿 MRI 病例中均存在不旋转的小肠位置，与产后发现相吻合，9 例病例中小肠位于胃对侧，1 例病例位于胃同侧（右侧腹部）。9 例病例中通过产前 MRI 观察到结肠，1 例病例因缺乏 T1 加权成像而受限。7 例病例中，不旋转的结肠位于小肠对侧。2 例病例中，结肠呈游走状，位于中线两侧。9 例病例中的结肠位置与产后发现相符。无病例出现产前肠梗阻。
产前 MRI 可检测到肠不旋转。
