Presentation
Developmental delay. Dilated occipital horns of the lateral ventricles on cranial ultrasound.
Patient Data



complete absence of the corpus callosum with absent septum pellucidum and hemispheric sulci
absent cingulate sulcus with the medial hemispheric sulci seen reaching the third ventricle in a radial fashion
dilated high-riding third ventricle
dilation of the occipital horns and prominent trigones, known as colpocephaly
parallel configuration of the lateral ventricles with narrow frontal horns - making the “racing car” sign on axial images and “Viking helmet” or “Moose head” signs on coronal images
Case Discussion
This case demonstrates the typical MRI features of corpus callosum agenesis.