PET Parses Alzheimer’s, Other Cognitive Impairments

Positron emission tomography (PET) scans using F-18 florbetaben (¹⁸F-FDG) clearly distinguished patients with Alzheimer’s disease from those with frontaltemporal lobar degeneration (FTLD) and other cognitive impairments, according to a study in the Journal of Nuclear Medicine.

A team led by radiologist Victor Villemagne, MD, of Austin Health in Heidelberg, Australia, considered 109 patients in three clinical studies with a variety of cognitive maladies. The subjects included 32 controls, 20 with mild cognitive impairment (MCI), 30 patients with Alzheimer’s disease, 11 with FTLD, seven with dementia with Lewy bodies, five with Parkinson’s disease, and four with vascular dementia.

FDG-PET scans showed Alzheimer’s patients to have “significantly higher” standard uptake value ratios (SUVRs) in neocortical areas: 96 percent of Alzheimer’s patients and 60 percent of those with mild cognitive impairment showed diffuse cortical ¹⁸F-FDG binding. That compares with 9 percent of those with FTLD, 25 percent of those with vascular dementia, 29 percent of those with dementia with Lewy bodies, 16 percent of the controls, and none of the Parkinson’s patients showing such cortical binding.

“¹⁸F-florbetaben had high sensitivity for AD, clearly distinguished patients with FTLD from AD, and provided results comparable to those reported with ¹¹C-Pittsburgh Compound B in a variety of neurodegenerative diseases,” the authors concluded.