Unlike prenatal Echo, fetal CMR is unaffected by fetal position. Fetal CMR with transverse views at the level of the aortic arch is a useful adjunct for the diagnosis of fetal aortic arch anomalies.

Objective: To retrospectively analyze the imaging findings of fetal intestinal obstruction diagnosed by MRI and compare with postnatal surgery findings. Methods: MRI data of 3346 pregnant women were retrospectively analyzed; we found 47 cases of suspected fetal small intestinal obstruction. Twenty-nine underwent postnatal surgery. Results: We identified one case of jejunal obstruction secondary to perforation, five annular pancreas, 10 duodenal stenoses, four jejunal stenoses, five jejunal atresias, two ileal atresias, four intestinal volvulus, and four intestinal malrotations. We further found four cases of duodenal stenosis with intestinal malrotation (two cases also showed volvulus). On fetal MRI, annular pancreas and duodenal obstruction manifested as a "double bubble." Jejunal stenosis appeared as a "triple bubble." Jejunal and ileal atresia mainly manifested as proximal dilatation with high signal on T1WI. Intestinal volvulus showed a sausage-like intestinal distortion and mixed signals on T1WI and DWI sequences. Intestinal malrotations were characterized as abnormal duodenal morphology. We missed two malrotations; one jejunal obstruction was misdiagnosed. Conclusion: Prenatal MRI can accurately determine the degree of intestinal obstruction and help qualitatively diagnose its possible etiology according to changes in MRI signals in multiple sequences, providing guidance for prenatal counseling.

Background: The aim of this study was to explore the magnetic resonance enterography (MRE) imaging manifestations of a symptomatic Meckel's diverticulum (MD) in pediatric patients in order to provide a reference for the diagnosis of the condition. Methods:The medical records of 31 pediatric patients with MD from May 2014 to October 2020 were retrospectively analyzed. The inclusion criteria were patients with MD accompanied by unexplained gastrointestinal bleeding, anemia (except hematological diseases), chronic persistent abdominal pain, repeated intussusception, or intussusception in older pediatric patients during surgery. The clinical variables (age, sex, and hemoglobin) and imaging, surgical, and pathological findings were recorded.Results: MD was definitively identified in 28 patients, with the following characteristics: a blind-ending fluid-filled and/or gas-filled structure (n=23), an elongated shape (n=1), a dumbbell shape (n=1), and a solid mass (n=3). The diverticula were located in the right lower quadrant (n=16), the right abdomen at the level of the umbilicus (n=3), the right upper quadrant (n=2), the left upper quadrant (n=2), and the midline lower abdomen (n=5). Supply arteries were visualized in nine cases. In all cases, mural enhancement was comparable to that of the adjacent small-bowel (SB). Extravasation of the intravascular contrast medium was seen in two cases. Peripheral structural abnormalities included mesenteric fat stranding (n=7), hemorrhage in the adjacent lumen (n=3), free intraperitoneal gas (n=1), abnormal fluid retention (n=2), intestinal obstruction (n=1), and lymph node enlargement (n=7). A normal appendix was identified in 18 cases.Conclusions: MRE is an appropriate method of diagnosing symptomatic MD in pediatric patients and is particularly useful in the assessment of complications.