QUANTITATIVE CT SCAN ANALYSIS IN SENILE DEMENTIA OF THE ALZHEIMER TYPE .1. COMPUTERIZED PLANIMETRY OF CEREBROSPINAL-FLUID AREAS

Sixty patients with senile dementia of the Alzheimer type (DAT) and 30 age and sex‐matched healthy controls were examined by cranial computed tomography (CT). We undertook this study to evaluate a simple and unbiased quantitative method for the estimation of ventricular and subarachnoid spaces by measuring areas of defined Hounsfield units (HUs) in four symmetric quadrants: left and right anterior, left and right posterior. The DAT patients showed a significant enlargement of all ventricles and all measured subarachnoid spaces (p< 0.001). These effects were not related to the age but to the diagnosis. They correlated with the duration of disease and partly with the degree of global cognitive impairment. Seventy‐eight per cent of the patients and controls could be classified correctly by means of the planimetric measurements. Copyright © 1991 John Wiley & Sons, Ltd.