Longitudinal Partial Volume Correction in 2-[18F]-Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography Studies of Alzheimer Disease

Objective To investigate partial volume correction (PVC) of 2-[F-18]-fluoro-2-deoxy-d-glucose positron emission tomography in Alzheimer disease in a longitudinal context. Methods A total of 115 participants were included, including 55 controls, 53 patients with mild cognitive impairment, and 7 patients with dementia of the Alzheimer type. Imaging was performed at baseline and 24 months. Partial volume corrected vs uncorrected rates of longitudinal change were compared for mesial temporal and cortical regions of interest. Results Partial volume correction increased apparent uptake, and this effect was greater at 24 months compared with baseline. Partial volume correction decreased the rate of decline, causing an apparent increase in uptake at 24 months compared with baseline. This effect was correlated with the structural atrophy. Conclusions These findings suggest that applying PVC in a longitudinal context in Alzheimer disease might produce unpredictable results. Accordingly, both PVC corrected and uncorrected data should be reported to ensure that the results are physiologically plausible.