16 channel head coil

Magnetic resonance imaging data of all participants were acquired in the resting condition using a 3.0T MRI scanner (Siemens Skyra, Munich) equipped with a 16-channel head coil at the Magnetic Resonance Imaging Center of Hunan Children’s Hospital, Changsha, China. None of the participants were taking any medications on the day of the MRI scan. Participants were instructed to remain awake and still in supine position with eyes closed. During the scanning, foam pads and earplugs were used to restrain head motion and to attenuate noise. Anatomical T1-weighted MRI data were acquired using a 3D magnetization preparing rapid acquisition gradient echo sequence with the following parameters: repetition time (TR) = 2,530 ms, echo time (TE) = 2.98 ms, flip angle = 7°, field of view = 256 × 256 mm, slice thickness = 1 mm, slice gap = 0 mm, voxel size = 1 × 1 × 1 mm³, number of slices = 176, and scanning time = 363 s. Functional images were obtained using a gradient echo-planar imaging (EPI) sequence with the following parameters: TR = 2,000 ms, TE = 30 ms, flip angle = 78°, field of view = 224 × 224 mm, slice thickness = 3.5 mm, slice gap = 0.7 mm, voxel size = 3.5 × 3.5 × 3.5 mm³, number of slice = 33, and scanning time = 488 s.

The participants were scanned in a 3T PET/MR Siemens Biograph mMR scanner with a vendor-supplied 16-channel head coil. They were instructed to fast for six hours prior to the scan session. After the intravenous injection of on average 102 ± 5 (SD) MBq of 18 F-FDG, the participants stayed comfortably in a quiet, dimly lit room, with closed eyes. Reconstructed PET images (30–60 min post-injection) had a voxel size of 1.04 × 1.04 × 2.03 mm³. Anatomical T1-weighted images were acquired with a magnetization‐prepared rapid gradient‐echo (MP‐RAGE) sequence with a voxel size of 1.0 × 1.0 × 1.0 mm³. DWI was performed using a single-shot EPI sequence of voxel size 2 × 2 × 2 mm³, with 30 diffusion directions with b = 800 s/mm² and one volume with b = 0 s/mm². For the fMRI acquisition, which lasted 8 min, participants were instructed to stay awake, close their eyes and think of nothing in particular. 212 volumes were acquired using a Prospective Acquisition Correction EPI sequence with voxel size of 3.0 × 3.0 × 3.0 mm³. An ultra-short echo time sequence was acquired for attenuation correction of the PET data. A dual echo gradient echo sequence was acquired to correct the DWI images for susceptibility induced distortions. Details of the PET and MR acquisitions are given in the supplementary material to our recent article.^{39 (link)}

Resting-state scans were obtained from the University of North Carolina samples at Greensboro¹ after request, without any rights conflicts. The participants were 28 elderly adults (61–80 years old, mean age ± standard: 69.82 ± 5.64; 20 female) and 34 young (18–32 years old, mean age ± standard deviation(SD): 22.21 ± 3.65; 20 female). Participants were instructed to lie motionlessly in the scanner and stay awake with their eyes open. All functional images were collected using a Siemens Trio 3.0T scanner with a 16-channel head coil and the following recording parameters: 32 slices with 4.0 mm thickness and no skip, time of echo = 30 ms; time of repetition (TR) = 2,000 ms; flip angle = 70, field of view = 220 mm, matrix size = 74 × 74 × 32 voxels, 300 volumes in 10 min.

The MRI data were scanned by a Siemens 3.0 T scanner (Germany) with a 16‐channel head coil at the Second Affiliated Hospital of Anhui Medical University. The whole scan took approximately 30 min. The rs‐fMRI image was scanned by a gradient‐recalled echo‐planar imaging (GRE‐EPI) pulse sequence. The rs‐fMRI data were obtained as follows: TE = 25 ms, TR = 2000 ms, acquisition matrix = 64 × 64, FA = 90°, FOV = 240 × 240 mm, thickness = 4.0 mm, gap = 0 mm, NEX = 1.0, slice number = 36, and time points = 240. The T1‐weighted 3D 3D‐SPGR images were obtained with the following parameters: TR = 1900 ms, TE = 2.48 ms, FA = 9°, acquisition matrix = 256 × 256, FOV = 240 × 240 mm, thickness = 1.0 mm, gap = 0 mm, slice number = 176, and NEX = 1.0. During the MRI scans, all patients were required to keep their eyes closed and avoid distraction during the scanning.