3.0 tesla mri system

In all subjects, MRI was performed at the same imaging session on 3.0 Tesla MRI system with 8-channel head coil (Siemens, Erlangen, Germany). First, conventional T1-weighted imaging (repetition time [TR]=250 ms, echo time [TE]=2.46, slices=19, slice thickness=5 mm, gap=1.5 mm, field of view [FOV]=220×220 mm) and T2-weighted imaging (TR=4,000 ms, TE=113 ms, slices=19, slice thickness=5 mm, gap=1.5 mm, FOV=220×220 mm) were collected. High-resolution T1-weighted images were acquired with a three-dimensional spoiled gradient-recalled echo sequence in a sagittal orientation with the parameters following: 176 images (TR=1,900 ms; TE=2.26 ms; thickness=1.0 mm; gap=0 mm; acquisition matrix=256×256; FOV=250×250 mm², flip angle=9°); 240 functional images (TR=2,000 ms; TE=30 ms; thickness=4.0 mm; gap=1.2 mm; acquisition matrix=64×64; flip angle=90°; FOV=230×230 mm²; 30 axial slices with gradient-recalled echo-planar imaging pulse sequence) were obtained.

All images were acquired using a 3.0 Tesla MRI system (Siemens, Munich, Germany) with an 8-channel phased-array head coil. First, conventional axial T2-weighted imaging (repetition time [TR] = 4000 ms, echo time [TE] = 113 ms, thickness = 5 mm, gap = 1.5 mm, field of view [FOV] = 220 mm × 220 mm, slice = 19) and axial T1-weighted imaging (TR = 250 ms, TE = 2.46 ms, thickness = 5 mm, gap = 1.5 mm, FOV = 220 mm × 220 mm, slice size = 19) were performed. High-resolution three-dimensional (3D) T1-weighted images were then obtained using a brain volume sequence (TR = 1900 ms, TE = 2.26 ms, thickness = 1.0 mm, gap = 0.5 mm, FOV = 250 mm × 250 mm, matrix = 256 × 256, flip angle = 9°, 176 sagittal slices). Finally, the rs-fMRI data were collected using an echo-planar imaging sequence with the following parameters: TR = 2000 ms, TE = 30 ms, flip angle = 90°, FOV = 230 mm × 230 mm, matrix = 64, thickness = 4 mm, gap = 1.2 mm. Each brain volume consisted of 30 axial sections, and each functional run consisted of 240 volumes. During the MRI scan, all participants were asked to close their eyes, remain as still as possible, not think about anything, and not fall asleep. Foam pads and earplugs were used to reduce head movement and scanner noise exposure. Two senior radiologists analyzed the images to exclude lesions and motion artifacts visible to the naked eye.