Imaging guidelines issued for Alzheimer disease

March 7, 2013

The first criteria for the appropriate use of positron emission tomography (PET) to aid in the diagnosis of Alzheimer disease (AD) have been published jointly by the Society of Nuclear Medicine and Molecular Imaging and the Alzheimer's Association.

Elevated levels of beta amyloid plaques in the brain are one of the defining pathologic features of AD. However, many otherwise normal elderly people have increased levels of these plaques, as do patients with conditions other than AD. Therefore, the clinical utility of PET imaging for beta amyloid plaques requires careful consideration.

The new guidelines state that appropriate candidates for amyloid PET imaging include patients with persistent or progressive unexplained mild cognitive impairment; patients satisfying core clinical criteria for possible AD (that is, atypical clinical course or etiologically mixed presentation); and patients with atypically young-onset dementia.