Neuroimaging and the differential diagnosis of early dementia: Quantitative CT scan analysis in patients attending a memory clinic

Seventy-eight consecutive patients who attended a ‘memory clinic’ underwent a standardized clinical examination including extensive laboratory tests and cranial computed tomography (CT). This brief report evaluates the contribution of quantitative CT scan analysis to the differential diagnosis of early dementia syndromes. Vascular changes were readily identified in 13 patients with a clinical history and findings compatible with vascular dementia. Enlargement of the anterior and Sylvian fissures and of the third and lateral ventricles was significantly more severe in a group of 29 patients diagnosed as Alzheimer's disease than in 36 ‘memory complainers’ with milder cognitive impairment or in 10 age-matched non-demented controls. Quantitative CT scan analysis alone permitted a correct diagnositc distinction between ‘memory complainers’ and patients with Alzheimer's disease in 83% of the cases, but led to an only modest improvement of the correct discrimination achieved by cognitive testing. Our results indicate that CT scans may aid the differentiation of ealry dementing conditions.