Erosion of The Supratentorial White Matter Reference for Increased Power in Longitudinal Amyloid PET
The use of the supratentorial white matter as a reference region, alone 1 7 or in composite 3 can facilitate the detection of subtle changes in amyloid plaque burden
Investigators often erode or otherwise restrict the sWM labels to reduce the influence of signal “spill in” from grey matter 2 4 8 but the optimal extent of erosion is unclear, and evaluations for 18 F radiotracers other than 18 florbetapir are scarce 8
The aim is to determine the optimal extent of erosion of the supratentorial white matter for use in a composite reference region, in longitudinal amyloid PET
Method
We evaluated the sensitivity of the eroded sWM using paired longitudinal amyloid PET and MR images acquired from participants who were cognitively normal or who had mild cognitive impairment , Alzheimer’s disease or subjective memory complaints at baseline.
IXICO’s multi region LEAP pipeline was used to automatically segment the contemporaneous T 1 w MRIs into 143 regions with high accuracy. We used our in-house PET analysis pipeline to process baseline and follow-up PET scans for each participant, including frame-to-frame realignment, co-registration, erosion of the sWM, quality control, and calculation of standardized uptake value ratios (SUVr)
Results
Outcome measures are reported as mean standard deviation over 10,000 samples (generated via bootstrapping with replacement).
Presented at AAIC 2024