Development of CT‐based regional Centiloid pipeline and application in Alzheimer’s disease cohort

Abstract

AbstractBackgroundStandard CL prosess was suggested to standardized measurement of amyloid deposition in amyloid PET imaging. In the present study, we aimed to develop CT based regional Centiloid scales using head to head comparison cohort of FMM and FBB PET. We also explored the clinical implications of our new CT based regional Centiloid scales investigating the effects of regional increased Aβ uptakes and striatal involvements of Aβ on brain structural and neuropsychological changes.MethodHead‐to‐head comparison dataset was included from 25 Alzheimer’s disease dementia (ADD) patients, 18 old controls (OC), and 20 young controls (YC) for FBB and FMM PET. We used direct comparison of FBB‐FMM CL (dcCL) method using MRI and CT images to define a common target region and six regional VOIs for all tracers. Clinical characteristics were compared to 2245 independent subjects in cognitive normal (CN), aMCI, and ADD. We also classified four stages using Centiloid cutoffs determined by machine learning technique. Among the subjects, regional Centiloid cutoffs were applied to classify four stages. The four stages were defined into focal (‐) and global (‐), F(‐)G(‐), F(‐)G(+), global (+) and striatum (‐), G(+)Str(‐), and G(+)Str(+) using determined Centiloid cutoffs. We also explored between the stages and clinical scores for cognition, structural changes.ResultHigh reliability and precision between MRI based and CT based Centiloid pipeline in quantification and Centiloid scales were found by head to head cohort. Those correlation of Centiloid scales were R2 = 0.91∼0.97 for paired PET tracers as head to head comparison and R2 = 0.95∼0.99 for same PET ligands between MRI based and CT based pipelines. In classified stages, F(‐)G(‐) stage was significantly different in comparison to G(+)Str(+) stage in CDR SOB, SVLT Delayed recall, hippocampal volume, and global cortical thickness (p<0.05).ConclusionOur proposed CT based Centiloid pipeline was validated by MRI based Centiloid pipeline, globally and regionally. Those applications into independent cohort were also validated by comparing cognitive scores and structural changes. Therefore, we demonstrated the new CT based regional Centiloid scales and the four stages by comparing cognitive score and structural changes in our independent cohort.