Descriptive analysis of prenatal MRI features of pathologically confirmed enteric duplication cysts

Abstract Background Fetal enteric duplication is prone to misdiagnosis, which can compromise prenatal counseling and comprehensive assessment. This study aims to investigate the magnetic resonance imaging (MRI) characteristics of fetal enteric duplication to improve its prenatal diagnostic accuracy and differential diagnosis. Methods A retrospective analysis was conducted on 36 postnatal surgically and pathologically confirmed cases of intestinal duplication, all of which were prenatally diagnosed by fetal MRI between September 2018 and May 2025. Prenatal MRI findings, postnatal clinical data, and pathological classifications were reviewed. Results The gestational age at the time of fetal MRI ranged from 26 to 39 weeks. The cohort included 21 female and 15 male fetuses. Thirty-one cases (86.1%) were isolated, while 5 (13.9%) were associated with other malformations. According to imaging morphology, 29 cases (80.6%) were cystic and 7 (19.4%) were tubular. Postnatal surgical pathology classified 10 cases (27.8%) as intraluminal and 26 (72.2%) as extraluminal. The lesion locations were: duodenum (1, 2.8%), jejunum (3, 8.3%), ileum/ileocecal region (28, 77.8%), ascending colon (1, 2.8%), and descending colon (3, 8.3%). The characteristic MRI features included well-defined, unilocular cystic lesions in the abdomen, demonstrating homogeneous long T1 and long T2 signals. The lesions exhibited a thick wall and were locally either sharing a common wall with or continuous with the adjacent bowel.The morphology was variable, appearing as round, oval, tubular, bilobed, or multilocular cysts, consistently located on the mesenteric side of the bowel with close contact to the intestinal wall and potential mass effect on adjacent loops. Conclusion Systematic evaluation of the relationship to the bowel, size, morphology, and signal characteristics on fetal MRI is crucial for the accurate prenatal diagnosis and differential diagnosis of intestinal duplication.