Evaluation of two clinical Centiloid analysis products for (18)F-florbetapir PET in cognitively unimpaired elders.

INTRODUCTION: Recently two software products (MIMneuro and Syngo.PET) received United States Food and Drug Administration (FDA) clearance for Centiloid analysis, thereby introducing Centiloid scoring to the clinical environment. This study compares Centiloid scores by these clinical products and conventional research methods. METHODS: (18)F-Florbetapir amyloid positron emission tomography (PET) scans (N = 252) of cognitively unimpaired elders were processed using both products and using research pipelines based on the Standard Centiloid method (magnetic resonance imaging [MRI]-based spatial normalization). RESULTS: Centiloid scores from both products were highly linearly correlated with each other (r(2 ) = 0.942) and with an MRI-based research pipeline having matching regions of interest (MIMneuro: r(2 ) = 0.942, Syngo.PET: r(2 ) = 0.971). However, Centiloid scores often differed by more than 10 Centiloids [CL] between methods, with Centiloid calibrations contributing to their inconsistency. DISCUSSION: Although Centiloid analyses were highly correlated, there was considerable variability in individual cases. Other factors not investigated (e.g., radiopharmaceutical, uptake time) could further contribute to variability. Clinicians should use caution when considering thresholds for amyloid positivity in individual cases. HIGHLIGHTS: Two newly available clinical software products, which provide rapid and simple Centiloid scoring, are compared to research processing involving both PET and MRI images.Excellent linear correlations were found among the methods.Centiloid scores for individual cases often differed by more than 10CL, which should be taken into consideration in clinical reporting.