Prenatal MRI diagnosis of fetal bowel obstruction

Abstract

Objective To investigate the clinical value of prenatal MRI in the diagnosis of fetal bowel obstruction. Methods Pregnant women suspected to have fetal abdominal abnormalities by ultrasonography were suggested to undergo MRI examinations within two days. Scanning sequence included FIESTA, SSFSE and T1WI SPGR sequence, with field of view focused on the fetal abdomen. After the final diagnoses of the cases were obtained by induced labor pathological examination or postpartum imaging or operation, the imaging data and the clinical data were reviewed and analyzed retrospectively. Results A total of 23 cases with bowel obstruction were included in the study. Four fetuses with duodenal atresia showed low T1 signal, high T2 signal characterized by double-bubble sign on MRI. There were 10 fetuses with jejunoileal atresia, showing bowel dilatation and hyperintense micro-colon on T1WI. Five cases of them depicted expansion of the terminal ileum with high T1 meconium signal.One each fetus had colonic atresia, intestinal malrotation with double-bubble and whirl sign. Annular pancreas with double-bubble sign and pressure trace of the bracket shape was detected in 3 fetuses. Meconium peritonitis was present in 4 fetuses, with 2 of them showing dilatation of intestine, ascites and pseudocysts. Conclusions According to the signal characteristics of amniotic fluid and meconium in the gastrointestinal tract on MRI, the obstructive level and development status of the distal bowel can be determined with MRI. It can provide additional information to ultrasonography, which brings clinical significance to prenatal diagnosis and intrapartum surgical operation. Key words: Magnetic resonance imaging; Fetus; Intestinal obstruction