The utility of CT scanning in diagnosing dementia

Dementia is an illness that affects an estimated 10% of noninstitutionalized persons older than 65 years of age. Among those older than 85 years of age, dementia is estimated to affect 20 to 50% of the population. The diagnosis of Alzheimer's disease is based on clinical criteria and the exclusion of other causes of dementia. Neuroimaging procedures, mostly CT scans, have been used to exclude other lesions presenting as dementia. The yield of these procedures has been estimated to be about 3%. This article reviews some of the literature on this topic in an effort to establish specific recommendations for neuroimaging procedures in patients who present with dementia.