Shiraz University Of Medical Science
Department of Radiology, University of California Davis Medical Center
Fetal gastrointestinal tract obstructions, while not
very common are among the potentially treatable fetal anomalies. The purpose of this study was to retrospectively review fetal MRI’s performed for evaluation of a suspected GIT obstruction in our center, correlate them with post-delivery follow-up and evaluate accuracy and value of MRI in diagnosis of these lesions.
Material and Methods:
The university ethics committee approved this retrospective study. 497 fetal MRI’s were done during2013-2016 in our institution. 21 studies were performed specifically for further evaluation of suspected GIT obstruction. Only fetuses in whom at least one-year post-delivery follow-up and/or pathology and operative results were available entered the study. 21fetal MRI’s were done for evaluation of suspected GI obstruction reported on anomaly US scan and followed to post-delivery /abortion to final diagnosis during2013-2016 in our institution, MRI’s were done on a Seimens Avanto 1.5T Scanner and interpreted with prior knowledge of the midtrimester anatomical survey. When operative diagnosis and pathology was not available, the fetuses were evaluated retrospectively in a multidisciplinary team including a radiologist, perinatologist, and pediatric surgeon. Results:
The final group included 12 GI tract obstruction with varying causes including small bowel atresia (4), esophageal atresia (3),midgut malrotaion (2), MMIHS ,anorectal malformation , external mass compression (each 1) . In 10 cases with distended stomach and suspected gastric outlet obstruction or duodenal atresia MRI was considered normal. In all of these cases third trimester ultrasound was normal. There was one case of anorectal malformation which was missed both by MRI and ultrasound.
US was sensitive for detecting GI obstruction (91%) but it was not specific(57%). This result is acceptable given the fact that ultrasound is a screening tool. Adding MRI to the ultrasound results increased the specificity significantly to 95% while the sensitivity remained unchanged at 91%.
When performed with prior knowledge of ultrasound results fetal MRI might be able to increase specificity of the diagnosis of fetal bowel obstructions in terms of level and cause of fetal bowel obstruction.
ologist, perinatologist, and pediatric surgeon.