Establishing Regional Aβ Cutoffs and Exploring Subgroup Prevalence Across Cognitive Stages Using BeauBrain Amylo^®

Area of Science:

• Neurology
• Radiology
• Biomarkers

Background:

• Amyloid-beta (Aβ) plaques are central to Alzheimer's disease (AD) pathology.
• Positron emission tomography (PET) enables Aβ quantification, but often requires MRI.
• Regional Centiloid scales (rdcCL) were developed for regional Aβ deposition analysis.

Purpose of the Study:

• Establish robust regional Aβ cutoffs using a commercialized CT-based platform (BeauBrain Amylo).
• Explore the prevalence of Aβ subgroups defined by global, regional, and striatal cutoffs across cognitive stages.

Main Methods:

• Utilized data from 2,428 individuals from the Korea-Registries to Overcome Dementia and Accelerate Dementia Research project.
• Calculated regional Aβ cutoffs via Gaussian Mixture Modeling.
• Classified participants into subgroups based on Aβ positivity across cognitive stages (cognitively unimpaired, mild cognitive impairment, dementia).

Main Results:

• CT-based and MRI-based global Aβ cutoffs showed high comparability.
• Regional cutoffs revealed modality-specific differences due to segmentation.
• Specific Aβ subgroup prevalences varied across cognitive stages and brain regions.

Conclusions:

• Established robust regional Aβ cutoffs using a CT-based rdcCL method.
• Demonstrated clinical utility in classifying amyloid subgroups across cognitive stages.
• Highlighted the importance of regional Aβ quantification for AD diagnosis and treatment.