Differences in anti-amyloid therapy eligibility assessment based on use of the SWI versus GRE sequence
Camilo Bermudez1, Jay J Pillai2,3, Brian J Burkett2
1Department of Neurology Mayo Clinic Rochester Minnesota USA.
Introduction:
The number of microhemorrhages (mHs) increases risk of amyloid-related imaging abnormalities (ARIAs) in those undergoing anti-amyloid treatments for Alzheimer's disease. It is unclear whether using different magnetic resonance imaging (MRI) sequences to detect mH would alter treatment decisions.
Methods:
We retrospectively analyzed 55 adults (mean age 72.1 ± 7.1 years) evaluated for cognitive concerns who had MRI exams including both susceptibility-weighted imaging (SWI) and gradient echo (GRE) sequences. Three neuroradiologists independently identified and then reached consensus on mH detection. Participants were classified into mH burden categories (none, 1, 2-4, ≥ 5).
Results:
Readers identified 83 mHs (mean 1.51) on SWI versus 54 (mean 0.98) on GRE. Burden categories agreed in 34 (61.8%) participants, was higher on SWI in 17 (30.9%) participants, and higher on GRE in 4 (7.3%) participants.
Conclusions:
Readers on average identified more mHs on SWI than GRE, altering risk categories. Prospective studies are needed to establish SWI-based safety thresholds for anti-amyloid therapies.
