Magnetom symphony system

MR images were acquired with a 1.5-T Magnetom Symphony system (Siemens Medical System, Erlangen, Germany) at Yokohama City University Hospital. A series of 128 contiguous T1-weighted slices in sagittal images was acquired with a Turbo FLASH sequence with the following parameters: echo time  = 3.93 ms, repetition time  = 1960 ms, inversion time  = 1100 ms, flip angle  = 15, field of view  = 24 cm, matrix  = 256×256×128, and voxel dimensions  = 0.9375×0.9375×1.5 mm. Intracranial content volumes were calculated with a MATLAB function.

Whole-brain fMRI data were collected using a 1.5 T scanner Magnetom Symphony system (Siemens) equipped with an 8-channel head coil. During the two regulation runs 506 functional T2^∗-weighted images were acquired in transversal direction using echo-planar imaging (EPI) with a repetition time (TR) of 4 s, Field of view (FoV) = 192 mm, matrix = 128 × 128, flip angle = 90°, echo time (TE) = 38 ms). Each functional volume comprised 33 slices (voxel sixe: 3 × 1.5 × 1.5 mm). Between the two functional runs, a high-resolution anatomical T1-weighted scan was acquired with a TR of 11 ms (FoV = 256 mm, matrix = 256 × 256, TE = 5.2 ms, voxel size: 1 × 1 × 1 mm).

We obtained structural brain MR images using a fast 3D-MPRAGE sequence (T1; TR, 2000; TE, 2.59; TI, 900; slice thickness 1.0mm) on a 1.5-T Magnetom Symphony System scanner (Siemens, Washington, DC). The images were used to help define anatomic regions and to generate gray matter maps for use in the 2FA PET imaging analyses. Hippocampal volume, proportional to intracranial cavity volume, was calculated for each participant using FreeSurfer (http://surfer.nmr.mgh.harvard.edu/) [42 (link)].