 Prominent susceptibility is seen along the right frontal region from indwelling shunt catheter which limits evaluation of surrounding structures. Grossly, the right frontal approach catheter is in stable position, with its tip just across midline in the interhemispheric region. Overall, the interhemispheric cystic spaces are reduced since the remote MRI and perhaps even slightly reduced since the more recent CT comparison. However, there has been overall interval fluctuation of the extra-axial cystic areas of the convexity. For example, a cyst along the posterior right parietal region has increasing convexity of its margins, now measuring 3.0 x 2.0 cm on 601/22, compared to previous 2.4 x 1.1 cm. However, there has been interval reduction of the overlying percent shaped cystic structure. Identifiable portions of the ventricular system do not appear significantly changed accounting for distorted anatomy since the previous MRI.Severe disordered gray matter with a nodular appearance replaces the majority of the superior right cervical hemisphere consistent with a migration abnormality of polymicrogyria. There is additional abnormal appearance of the gray matter along the left posterior parietal lobe consistent with additional polymicrogyria. There appears be complete absence of the corpus callosum. There is slight distorted appearance of the cerebellum with perhaps mild dysplasia.There are no areas of abnormal signal other than scattered minimal areas of marginal FLAIR hyperintensity consistent with areas of gliosis. There is no diffusion abnormality.Normal flow-voids are demonstrated in the major intracranial vascular structures. The midline structures and craniocervical junction are within normal limits.
1.Overall, no significant interval change in dysmorphic ventricular size, with stable decreased interhemispheric and fluctuating size of convexity extra-axial cystic structures. Right frontal approach drainage catheter remains in grossly stable position.2.Redemonstration of extensive developmental abnormalities including multifocal polymicrogyria and absence of the corpus callosum.