MRI acquisition and pre-processing
The MESA Exam 6 Atrial Fibrillation (AFib) Ancillary Study’s34 brain MRI protocol included T1-weighted (T1w) and T2-weighted (T2w) sequences, and a susceptibility weighted imaging (SWI) sequence with 4 different, equally spaced echo times. SWI is a high-resolution, 3D imaging sequence where the image contrast is enhanced by combining magnitude and phase image data43,44. The scans were acquired at 6 sites using the same acquisition parameters. All scans were performed on Siemens MR scanners (2 Skyra with a 20-channel head coil and 4 Prisma Fit with a 32-channel head coil) at a static magnetic field strength of 3 Tesla and identical imaging sequence parameters, as shown in Supplementary Table 1.1 in Sect. 1 of the “Supplementary materials”.
Multiple SWI phase and magnitude images were acquired with varying echo times (Supplementary Table 1.1 in…
