A universal neocortical mask for Centiloid quantification

Pierrick Bourgeat, CSIRO Health and Biosecurity
Vincent Doré, CSIRO Health and Biosecurity
Christopher C Rowe, University of Melbourne
Tammie Benzinger, Washington University School of Medicine in St. Louis
Duygu Tosun, University of California, San Francisco
Manu S Goyal, Washington University School of Medicine in St. Louis
Pamela LaMontagne, Washington University School of Medicine in St. Louis
Liang Jin, University of Melbourne
Michael W Weiner, University of California
Colin L Masters, University of Melbourne
Jurgen Fripp, CSIRO Health and Biosecurity
Victor L Villemagne, University of Pittsburgh
Alzheimer's Disease Neuroimaging Initiative
OASIS3, and the AIBL research group

Abstract

INTRODUCTION: The Centiloid (CL) project was developed to harmonize the quantification of amyloid beta (Aβ) positron emission tomography (PET) scans to a unified scale. The CL neocortical mask was defined using

METHODS: Using data from the Alzheimer's Dementia Onset and Progression in International Cohorts (ADOPIC) study (Australian Imaging Biomarkers and Lifestyle + Alzheimer's Disease Neuroimaging Initiative + Open Access Series of Imaging Studies), age-matched pairs of mild Alzheimer's disease (AD) and healthy controls (HC) were selected:

RESULTS: In the GAAIN dataset, the universal mask led to a small reduction in the variance of the YC, and a small increase in the inter-tracer agreement. In the ADOPIC dataset, it led to a better separation between HC/AD and HC/MCI at baseline.

DISCUSSION: The universal CL mask led to an increase in inter-tracer agreement and group separation. Those increases were, however, very small, and do not provide sufficient benefits to support departing from the existing standard CL mask, which is suitable for the quantification of all Aβ tracers.

HIGHLIGHTS: This study built an amyloid universal mask using a matched cohort for the five most commonly used amyloid positron emission tomography tracers.There was a high overlap between each tracer-specific mask.Differences in quantification and group separation between the standard and universal mask were small.The existing standard Centiloid mask is suitable for the quantification of all amyloid beta tracers.