Trio 3.0t mri scanner

All subjects were scanned with a Trio 3.0 T MRI scanner (Siemens, Munich, Germany) following a standardized protocol: (1) resting-state functional MRI (rs-fMRI) acquisition [repetition time (TR)/echo time (TE) = 2000/30 ms, flip angle (FA) = 90°, matrix = 64 × 64, field of view (FOV) = 210 × 210 mm, and 240 time points]; (2) high-resolution 3D T1-weighted image acquisition (TR/TE = 1900/2.26 ms, matrix = 240 × 256, FOV = 215 × 230 mm, and 176 sagittal slices); (3) T2-fluid attenuated inversion recovery (FLAIR) sequences (TR/TE = 7000/77 ms, inversion time = 2500, FA = 120°, slice thickness: 2 mm, and 50 slices). During rs-fMRI acquisition, subjects were asked to close their eyes, relax and remain awake with minimal specific thinking.

All participants in the discovery sample underwent both structural and functional image scanning using a Siemens Trio 3.0 T MRI scanner (Siemens, Malvern, PA, USA) at Southwest University, Chongqing, China. The structural images were acquired from a high resolution, T1-weighted magnetization-prepared rapid gradient echo sequence (repetition time = 1900 ms, echo time = 2.52 ms, inversion time = 900 ms, flip angle = 9°, field of view = 256 × 256 mm², matrix = 256 × 256, voxel size = 1 × 1 × 1 mm³, and slices = 176). The resting-state fMRI images were obtained using a single-shot, gradient-recalled echo planar imaging sequence (repetition time = 2000 ms, echo time = 30 ms, flip angle = 90°, field of view = 220 × 220 mm², matrix = 64 × 64, voxel size = 3.4 × 3.4 × 3 mm³, and slices = 32). For each subject, a total of 242 volumes (484 s) were acquired. All participants were instructed to simply rest with their eyes closed. The data acquisition of the replication sample is detailed in the Supplementary Materials.

MRI data were obtained from a Siemens (Erlangen, Germany) Trio 3.0 T MRI scanner, equipped with a 12-channel head coil. We obtained anatomical images (T1-weighted) using these parameters: 176 slices, flip angle 9°, matrix 256 × 256, echo time (TE) 2.26 ms, inversion time (TI) 900 ms, repetition time (TR) 1900 ms, and voxel size 1 × 1 × 1 mm³. We then obtained resting images with an echo-planar imaging (EPI) sequence: voxel size 3.75 × 3.75 × 5 mm³, 240 volumes;, TE 30 ms, TR 2000 ms, field of view 240 × 240 mm², matrix 64 × 64, interslice gap 0 mm, slice thickness 5 mm, 30 slices, and flip angle 90°. We used foam pads and ear plugs to reduce head motions and noise perception; during resting scans, participants were indicated to lie still, to close their eyes but remain awake, and to not thinking of things on purpose.

MRI data were acquired using a Trio 3.0 T MRI scanner and an 8-channel phase-controlled head coil (Siemens, Munich, Germany). During the scan, each subject was kept in a supine position with foam pads used to reduce head movement, wore earplugs, and was asked to close their eyes, relax, and remain awake with minimal specific thinking. Resting-state fMRI (rs-fMRI) images, high-resolution 3D T1-weighted and CE T1-weighted images were obtained for each participant using the following sequences:

All participants were scanned using a Siemens Trio 3.0 T MRI scanner at XuanWu Hospital of Capital Medical University. Participants lay still with their heads fixed by straps and foam to minimize movement. The T1-weighted images were acquired using a magnetization prepared rapid gradient echo (MPRAGE) sequence with the following parameters: repetition time (TR) = 1,900 ms; echo time (TE) = 2.2 ms; flip angle = 9°; acquisition matrix = 256 × 224; field of view (FOV) = 256 × 224 mm²; slice thickness = 1 mm; no gap; 176 sagittal slices; and average = 1. The diffusion tensor imaging (DTI) data were acquired using a single-shot EPI sequence with the following parameters: TR = 11,000 ms; TE = 98 ms; flip angle = 90°; acquisition matrix = 128 × 116; FOV = 256 × 232 mm²; slice thickness = 2 mm; no gap; 60 axial slices; and average = 3. Thirty non-linear diffusion weighting directions with b = 1,000 s/mm² and one b0 image were obtained. All images were reviewed and the leukoencephalopathy and vascular comorbidity was evaluated by an experienced neuroradiologist.

Magnetic resonance imaging (MRI) of the brain was also completed at Emory University (3.0-T Trio MRI scanner; Siemens Medical Solutions). High-resolution T1-weighted images were acquired using a magnetization-prepared rapid gradient-echo imaging sequence with field of view of 256 × 256 mm²; 176 sagittal slices; isotropic voxel resolution, 1.0 mm³; repetition time, 2300 milliseconds; echo time, 2.89 milliseconds; inversion time, 800 milliseconds; flip angle, 8°; and scan duration, 8 minutes 37 seconds. Quality checks included head motion detection and/or correction, atlas registration confirmation, and visual inspection of images.
Hippocampal volume and other volumetric measurements were calculated using the FreeSurfer package, version 6.0.0, with manual supervision. Quality checks were performed for each scan. Left and right hippocampal volumes were obtained and combined to derive the total hippocampal volume. Intracranial volume was also derived from this analysis. Volumetric measurements using FreeSurfer have been shown to provide similar estimates to a fully manual procedure.^{16 (link)} We used intracranial volume–adjusted hippocampal volume to reflect the degree of neurodegeneration for each participant.^{4 (link)}