Radiology 2003 Feb;226(2):315-36
Neuroimaging and early diagnosis of Alzheimer disease: a look to the future.
Petrella JR, Coleman RE, Doraiswamy PM.
Alzheimer disease (AD), a progressive neurodegenerative disorder, is the most
common cause of dementia in the elderly. Current consensus statements have
emphasized the need for early recognition and the fact that a diagnosis of AD
can be made with high accuracy by using clinical, neuropsychologic, and imaging
assessments. Magnetic resonance (MR) or computed tomographic (CT) imaging is
recommended for the routine evaluation of AD. Coronal MR images can be useful to
document or quantify atrophy of the hippocampus and entorhinal cortex, both of
which occur early in the disease process. Both volumetric and subtraction MR
techniques can be used to quantify and monitor dementia progression and rates of
regional atrophy. MR measures are also increasingly being used to monitor
treatment effects in clinical trials of cognitive enhancers and antidementia
agents. Positron emission tomography (PET) and single photon emission CT offer
value in the differential diagnosis of AD from other cortical and subcortical
dementias and may also offer prognostic value. In addition, PET studies have
demonstrated that subtle abnormalities may be apparent in the prodromal stages
of AD and in subjects who carry susceptibility genes. PET ligands are in
late-stage development for demonstration of amyloid plaques, and human studies
have already begun. Functional MR-based memory challenge tests are in
development as well. Copyright RSNA, 2003
