Optimisation and usefulness of quantitative analysis of 18F-florbetapir PET

Objectives: This study investigates the usefulness of quantitative SUVR thresholds on sub types of typical (type A) and atypical (non-type A) positive (Aβ+) and negative (Aβ-) 18F-florbetapir scans and aims to optimise the thresholds. Methods: Clinical 18F-florbetapir scans ( n = 100) were categorised by sub type and visual reads were performed independently by three trained readers. Inter reader agreement and reader-to-reference agreement were measured. Optimal SUVR thresholds were derived by ROC analysis and were compared with thresholds derived from a health control group and values from published literature. Results: Sub type division of 18F-florbetapir PET scans improves accuracy and agreement of visual reads for type A: accuracy 90%, 96 and 70 % and agreement κ > 0.7, κ ≥ 0.85  and − 0.1 < κ < 0.9 for all data, type A and non-type A respectively. Sub type division also improves quantitative classification accuracy of type A: optimum mcSUVR thresholds were found to be 1.32, 1.18 and 1.48 with accurac...