<prompt> Extensive involvement of deep white matter with bilateral hyperdense thalami on non-contrast CT scan of the brain is viually diagnostic of:Alexanders diseaseKrabbes diseaseCanavans diseaseMetachromatic leukodystrophy  <response>: B i.e., Krabbes disease Krabbes diseases Globoid cell leukodystrophy is characterized by: Focal bilateral thalamic, posterior internal capsule and basal ganglia lesion showing hyperdensity calcification in CT scanQ and hypointensity on T2 MRI. Extensive involvement of deep white matterQ, more severely posteriorly centrally. - Cerebellar white matter abnormality sparing the dentate nuclei; involvement of pyramidal tracts within brain stem. MCT shows hypodensity of white matter. MRI- T2 image also detect abnormality in deep periventricular white matter with cavitatory changes, adjacent to frontal horns. 