Abstract
Purpose: Digital PET cameras markedly improve sensitivity and spatial resolution of brain 18F-FDG PET images compared to conventional cameras. Our study aimed to assess whether specific control databases are required to improve the diagnostic performance of these recent advances.Methods: We analysed twenty-seven Alzheimer's Disease (AD) patients and twenty-two healthy subjects. These two groups underwent a brain 18F-FDG PET on a digital camera (Vereos, Philips®) with a Semi-Quantitative Analysis (SQA), i.e. comparisons to two age and sex matched controls acquired with a digital PET (Vereos, Philips®) and a conventional PET (Biograph 6, Siemens®) camera, at group and individual levels. Moreover, individual visual interpretation of SPM T-maps was provided for the positive diagnosis of AD by 3 experienced raters.Results: At group level, SQA using digital controls detected more marked hypometabolic areas in AD (+34 mm3 at p<0.001 uncorrected for the voxel, corrected for the cluster) than SQA using conventional controls. At the individual level, accuracy of SQA using digital controls was higher than SQA using conventional controls (82 vs. 63%, p<0.01, at p<0.005 uncorrected for the voxel, corrected for the cluster), with lower specificity (73 vs. 95%) but much higher sensitivity (89 vs. 37%). These results were confirmed by visual analysis (accuracies of 78% and 65% for digital and conventional controls respectively).Conclusion: There is an urgent need to establish specific digital PET control databases for SQA of brain 18F-FDG PET images as such databases improve the accuracy of AD diagnosis.