[CT study of brain atrophy--the value of various study methods].

55 rather young patients suspected of dementia were examined via CT to assess the comparative value of various CT examination methods to determine cerebral atrophy. The patients were assessed clinically and classified as normal (24), slightly demented (21) and moderately demented (10). There were no severely demented patients. The parameters measured consisted of several diameters and indexes as well as the volume of the ventricular system and of the subarachnoidal space. The atrophy level was also determined visually. With the exception of the breadth of the third ventricle there was no correlation between internal cerebral atrophy and the level of dementia. Neither the mean breadths of four external sulci nor the volume of the subarachnoidal space (both being representative of external atrophy) showed any significant correlation with the degree of dementia of the patients on the levels 0.005 or 0.025, respectively. However, the results were not better than those obtained by visual assessment of external atrophy. Reasons are discussed why objective measurements do not yield reliable results.