Evaluation of cortical atrophy between progressive supranuclear palsy and corticobasal degeneration by hemispheric surface display of MR images.

BACKGROUND AND PURPOSE Three-dimensional imaging and hemispheric volumetry are useful for the assessment of degenerative cortical atrophy. Our purpose was to determine the features of cortical atrophy in progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) by means of a hemispheric surface display generated with MR images. METHODS The extent of cortical atrophy was evaluated with automated MR hemispheric surface display and volumetry in 19 patients with PSP and 19 with CBD. RESULTS Most cortical regions were less atrophic in PSP than in CBD. The parietal lobe, paracentral regions, anterior middle frontal lobe, and posterior inferior frontal lobe were significantly more atrophic in CBD than in PSP, whereas the brainstem was significantly more atrophic in PSP. The mean hemisphere-to-intracranial volume ratio was significantly greater in patients with PSP (74.5%) than in those with CBD (71.4%), whereas the mean brainstem-to-intracranial volume ratio was significantly smaller in PSP (1.4%) than in CBD (1.6%). Asymmetry of hemispheric volume was significantly larger in the CBD group than in the PSP group. CONCLUSION Hemispheric surface display and volumetry are generally helpful and especially useful for the differentiation of PSP and CBD.