Dynamic susceptibility contrast MR imaging for the evaluation of probable Alzheimer disease: a cost-effectiveness analysis.

Abstract

Alzheimer disease (AD) is an organic dementia which accounts for approximately 70% of dementia cases in industrialized countries. Currently, Alzheimer disease affects over 4 million Americans at an annual cost of $80 billion. The prevalence of this debilitating illness increases with age from 10% at age 65 to 47% by age 85 (1,2). The initial diagnosis of AD is often made clinically at a stage when the patient's function has been extensively compromised; therefore, imaging in AD patients is usually performed as a confirmatory test. Morphologic abnormalities (such as cortical atrophy and ventricular enlargement) are assessed by means of magnetic resonance imaging (MRI) or computed tomography (CT) (3-5), while cerebral-perfusion abnormalities are usually assessed using nuclear medicine techniques such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT) (5-11). Recent studies have suggested the possibility of using dynamic susceptibility contrast MRI (DSC MRI) to assess brain perfusion in patients with Alzheimer disease (1214). DSC MRI involves the use of high-speed MRI and a bolus injection of contrast material to generate maps of cerebral blood volume (15-17). Analysis of the resulting images provided a reliable measurement of regional cerebral