Accelerated MRI Sequences for Intracranial Hemorrhage Screening.

Area of Science:

• Neuroimaging
• Radiology
• Biomarkers

Background:

• Anti-amyloid-beta immunotherapy necessitates frequent MRI screening for ARIA-H (cerebral microbleeds/superficial siderosis).
• Current MRI sequences (GRE, SWI) are time-consuming, potentially limiting patient enrollment and increasing motion artifacts.
• Accelerated MRI techniques may improve screening efficiency and patient throughput.

Purpose of the Study:

• To evaluate the diagnostic performance of echo-planar imaging (EPI) accelerated GRE (aGRE) and SWI (aSWI) substitutions for detecting CMB and SS.
• To compare accelerated sequences against standard GRE and SWI in terms of sensitivity, specificity, and predictive values.
• To assess the impact of acceleration on image quality, motion, and rater agreement.

Main Methods:

• Retrospective analysis of 50 patients undergoing FDG PET-3T MRI.
• Comparison of standard GRE (90s) and SWI (192s) with EPI-accelerated aGRE (13s) and aSWI (33s).
• Independent assessment by three neuroradiologists for CMB and SS detection, image quality, and motion, with calculation of AUC, PPV, NPV, and inter-rater agreement.

Main Results:

• Excellent aggregate AUCs for both CMB (0.84-0.94) and SS (0.89-1.00) across all sequences, with no significant differences between standard and accelerated methods.
• High negative predictive values (96.5%-100%) for both aGRE and aSWI.
• Mildly reduced inter-rater agreement for accelerated sequences compared to standard, and reduced perceived image quality, though aSWI showed less motion.

Conclusions:

• EPI-accelerated aGRE and aSWI sequences offer substantial time savings (86% and 83%) for ARIA-H screening.
• These accelerated sequences demonstrate comparable diagnostic performance to standard GRE and SWI for detecting CMB and SS.
• While accelerated sequences reduce rater agreement and perceived image quality, they represent a viable option for efficient ARIA-H screening.