Sensitivity and specificity of neuroimaging for the diagnosis of Alzheimer's disease.

Alzheimer's disease (AD) is one of the most devastating and cosily disorders affecting the aging population. Structural imaging (computed tomography [CT] and magnetic resonance imaging [MRI]) and functional imaging (single photon emission computed tomography [SPECT] and positron emission tomography [PET]) have been evaluated for their roles in the imaqinq diagnosis of AD. We have reviewed the recent literature to determine the capabilities of these neuroimaging techniques in comparison to current standards of clinical diagnosis. Our results indicate that there is wide variability in the accuracy of clinical assessments, in contrast to a more limited ranqe of variability of the accuracy of neuroimaqinq measurements. These results suggest that neuroimaging may serve an adjunctive role in raising this lower bound of diagnostic accuracy. Furthermore, we suggest that neuroimaging should be considered: (I) when clinical expertise is insufficient; (il) as a complement to specific likelihood ratios; and (iii) in specific types of patients, for whom clinical evaluation is inappropriate or inadequate.