3 tesla discovery mr 750 scanner

The same scanners and protocols were used at both data collection waves (baseline and follow up). MRI was performed with a 3 tesla Discovery MR 750 scanner (General Electric, WI, US), equipped with a 32-channel phased-array head coil. PET data were acquired with a Discovery PET/CT 690 (General Electric, WI, US) and 250 MBq ¹¹C-raclopride. At each data collection wave, MRI and PET was performed on two different days, separated by a maximum of 1 week.

The fMRI session in experiment 2 was conducted at 3T with a GE 3 Tesla Discovery MR750 scanner with a 32-channel receive-only head coil. Each subject underwent one session with two functional runs (784 volumes each) of scanning using a T2^*-weighted gradient echo pulse sequence, echo planar imaging, field of view = 25 cm, matrix size = 96 × 96, slice thickness = 2.9 mm, 37 slices with no inter-slice skip and an ASSET acceleration factor of 2. The volumes covered the whole cerebrum and most of the cerebellum, the acquisition orientation was oblique axial and aligned with the anterior and posterior commissure, and was scanned in interleaved order with TE = 30 ms, TR = 2 s, flip angle = 90°. Between the two functional runs a high-resolution T1-weighted structural image was collected FSPGR with TE = 3.2 ms, TR = 8.2 ms, TI = 450 ms, and flip angle = 12°.

Magnetic resonance (MR) imaging was performed with a 3 tesla Discovery MR 750 scanner (General Electric) equipped with a 32-channel phased-array head coil. PET was done with a Discovery 690 PET/CT scanner (General Electric).