Abstract
There is greater interest in amyloid biomarker for the diagnosis of Alzheimer disease (AD) with the recent Food and Drug Administration approval of amyloid-targeted therapy. The goal of this study was to assess the clinical utility of amyloid positron emission tomography (PET) in clinically ambiguous cases of cognitive impairment by examining outcomes of patients enrolled in the Imaging Dementia-Evidence of Amyloid Scanning study at 2 academic institutions. Of the 112 patients in the study, 66.1% (n=74) of patients had a positive amyloid PET scan, and 33.96% (n=38) had a negative amyloid PET scan. Lower cognitive test scores were predictive of positive amyloid PET scan ( P =0.001). Eighty-two percent (92/112) of the patients were seen for follow-up. Of the 30 patients with negative amyloid PET scan results, 90% had a diagnosis of non-AD etiology after receiving the negative results, suggesting a negative amyloid scan can be used to rule out AD diagnosis.