Visual read performance of 18F‐Florbetapir and 18F‐NAV4694 Aβ PET compared against Centiloid reference standard in a paired cohort

Abstract INTRODUCTION Visual assessment remains standard practice to rule out amyloid‐β (Aβ) pathology. 18F‐NAV4694 (NAV) has high affinity for Aβ potentially detecting lower levels than other F‐18 Aβ tracers. METHODS One hundred fifty participants in the AIBL study underwent both 18F‐Florbetapir (FBP) and NAV Aβ PET scans. PET scans were assessed by six nuclear medicine physicians against Centiloid (CL) quantification. An optimized reference region was utilized for FBP as it improved CL–visual read correlations. Inter‐reader agreement of visual assessment was measured using Fleiss’ Kappa. RESULTS Mean peak accuracy for visual read exceeded 95% for both NAV and FBP. However, peak accuracy for NAV visual reads was achieved at 14–15CL compared to 38–46CL for FBP. Higher inter‐reader agreement was observed for NAV compared to FBP. DISCUSSION For mild to moderate elevation in Aβ, visual read of NAV is more sensitive and consistent than visual read of FBP by both experienced and novice readers.