The axial MR head shows a large posterior fossa cyst with a wide communication between the 4th ventricle and the posterior subarachnoid enlarged posterior fossa. Dysgenesis of the cerebellar vermis and superior cerebellar peduncles showing as the molar tooth sign, is present. Furthermore, a wide CSF cleft communicating the medial aspect of the left lateral ventricle with the superomedial subarachnoid space, in keeping with open-lip schizencephaly, is noted.