Accelerated 3D MRI for ARIA monitoring in Alzheimer's disease

Abstract INTRODUCTION Amyloid‐targeting therapies for Alzheimer's disease require regular MRI monitoring for amyloid‐related imaging abnormalities (ARIA). 3D scans are more sensitive but time intensive; ultra‐fast implementations could improve access and reduce burden. METHODS Eighty scans from 20 participants were acquired with standard 2D fluid‐attenuated inversion recovery (FLAIR) and T2*‐gradient recalled echo (T2*‐GRE), or accelerated Wave‐controlled aliasing in parallel imaging (Wave‐CAIPI) 3D FLAIR and susceptibility‐weighted imaging (SWI) at 3 T. Two neuroradiologists graded ARIA‐E (edema/effusion) and ARIA‐H (hemosiderin deposits). Bayesian models estimated sensitivity, specificity, severity agreement, and interchangeability between acquisitions. RESULTS Accelerated sequences reduced acquisition time by up to 56%. Four participants had ARIA‐E and microbleeds; five had microbleeds alone. Sensitivity and specificity for ARIA‐E were identical (1.00; 0.94–0.95); severity was comparable. Replacing standard with accelerated FLAIR did not decrease severity agreement (interchangeability 1.4; 95% highest‐density interval HDI −3.6% to 5.4%). Fast SWI showed higher microbleed severity gradings. DISCUSSION Wave‐CAIPI offers fast high‐resolution FLAIR acquisitions with comparable performance for ARIA‐E monitoring. Wave‐CAIPI SWI provides high‐quality scans that may aid ARIA‐H interpretation.