HAI Book 2025 - Flipbook - Page 238
Bezgin, Gleb
54
Comparison of distribution volume and standardized uptake value
ratio for a MAO-B tracer in mild cognitive impairment
Gleb Bezgin1, Nesrine Rahmouni1, Ryuichi Harada2, Nobuyuki Okamura2, Andrea Lessa
Benedet3, Nicholas Ashton3, Henrik Zetterberg3, Kaj Blennow3, Pedro Rosa-Neto1
1
McGill University, Montreal, QC, CA
Tohoku Medical and Pharmaceutical University, Sendai, JP
3
University of Gothenburg, Gothenburg, SE
2
Introduction: SMBT-1 is a promising PET tracer for Monoamine Oxidase-B (MAO-B) imaging1. While selective and
sensitive for Alzheimer's disease (AD), methods to quantify this family of tracers are being improved. Here, using a
sample of subjects from an AD cohort, we compare results obtained using distribution volume (DV) and
standardized uptake value ratio (SUVR). Using both techniques, we explore the association between these PET
metrics and several plasma biomarkers (GFAP, p-tau-217, p-tau-231 YKL-40 and Abeta42/40 ratio).
Methods: We administered SMBT-1 on fourteen subjects from the TRIAD cohort2 (7 cognitively normal (CN), 4 with
mild cognitive impairment (MCI), 2 with non-AD pathology; mean age 71.9). The scanning was performed using
High-Resolution Research Tomograph (HRRT), and the MRI was done on a SIEMENS Prisma scanner. For the PET
images, we computed DV and SUVR, using cerebellar grey as reference region. Proteomics data for plasma GFAP,
p-tau-217, p-tau-231, Abeta40, Abeta42 and YKL-40 were obtained using NULISA3. The association between
DV/SUVR images and fluid biomarkers was assessed using VoxelStats4.
Results: Time activity curves for MCI had more sustained tracer retention than those of CN subjects, resulting in
generally higher DV values (Fig.1A). VoxelStats analyses showed that DV and SUVR were generally consistent in
capturing association between PET data and plasma biomarkers (Fig.1B). GFAP, p-tau-217 and p-tau-231 showed
association with voxels around precuneus and medial frontal, whereas YKL-40 was most associated with
periventricular white matter. Abeta42/40 relationship with DV had scattered cortical distribution; this association
was moderate and marginally significant (r=-0.5; p=0.07; Fig.1C-left). GFAP correlated with the whole cortex
average of SUVR (r=0.7; p
