Detailed evaluation of commissural agenesis in fetuses suspected with agenesis of corpus callosum, a fetal MRI Study

Purpose: To evaluate accompanying agenesis of other commissures including anterior commissure and hippocampal commissure in fetuses with agenesis of corpus callosum.Material and Methods: This retrospective study was approved by university ethics committee. Out of 821 fetal MRI’s that were done during 2017-2018 in our institution, fetuses with 34 fetuses with confirmed callosal agenesis entered the study. MRI’s were done on a Seimens Avanto 1.5T Scanner and interpreted with prior knowledge of the midtrimester anatomical survey. Retrospective evaluation of the fetal MRI s for associated commissural agenesis was done.Result: The MR imaging studies of 167 fetals suspected with ventriculomegaly with ultrasound were reviewed to evaluate types of abnormalities of the corpus callosum. MRI confirmed ventriculomegaly in 94 cases. In 45 (47.8%) out of 94 cases with ventriculomegaly the anomaly of corpus callosum was suspected in ultrasound. Complete corpus callosum agenesis in 19 Cases and partial agenesis of the corpus callosum in 11 cases were identified, and the remaining 15 cases had normal corpus callosum. In fetuses with complete callosal agenesis anterior commissure was visible in 11 out of 19, hippocampal commissure in 2 out of 19 and none in 6 out of 19 fetuses.Conclusion: Anterior commissure is present in many cases of callosal agenesis. Details of other commissural agenesis might become clinically relevant when later follow-up studies establish its association with neurodevelopmental outcome