 Stigmata of agenesis of the corpus callosum is again seen. The ventricles and sulci are stable in size, even comparing back to more remote MRI comparisons. There is again diffuse significant dilatation of the supratentorial ventricles.There has been interval decrease in size of the left frontoparietal chronic subdural collection which is increased in homogeneity with minimal residual collection measuring up to 0.7 cm in maximum dimension compared to 1.0 cm previously. There is essentially stable prominence of extra-axial space of CSF signal intensity along the right interhemispheric fissure, anterior right greater than left frontal lobe, as well as along both anterior temporal lobes. On T2/FLAIR images, there is suggestion of possible thin septations within these areas of extra axial space prominence, in addition to minimal peripheral vasculature. There is persistent flattening of the anterior temporal lobes which may suggest arachnoid cysts, which is stable from previous exam. Stable focal prominence of T2 hyperintensity within the midline posterior fossa may be likely related to cisterna magna versus retrocerebellar cyst.There are no areas of abnormal parenchymal signal. There is no diffusion abnormality. Normal flow-voids are demonstrated in the major intracranial vascular structures. There is mild mucosal thickening in the maxillary sinuses.
1. Slight reduction in the size of the left frontoparietal extraaxial chronic collection. 2. Stable findings of complete agenesis of corpus callosum. 3. Stable dilatation of extra-axial space especially anteriorly, with possible middle cranial fossa arachnoid cysts.