Eight channel head coil

A 3.0-T Philips MRI scanner (Ingenia, Netherlands) with an eight-channel head coil was used to MRI data acquisition. The patients were asked to reflex and close their eyes, but without falling asleep. Rs-fMRI images were obtained using echo-planar imaging sequence whose parameters were 36 slices, 2000 ms as the repetition time (TR), 30 ms echo time (TE), thickness of 3.5 mm, no gap, voxel size of 3.75 mm × 3.75 mm × 4.0 mm, 90° flip angle, 240 mm × 240 mm field of view (FOV), 64 × 64 data matrix, and 230 volumes. The fMRI sequence was completed in 8 min and 8 s. A 3D turbo fast echo T1WI sequence was used to obtain structural images. Its parameters were 170 slices, TR/TE = 8.1/3.7 ms, thickness of 1.0 mm, gap of 0 mm, FOV = 256 mm × 256 mm, 256 × 256 acquisition matrix, and FA = 8°. Structural sequences were completed in 5 min and 29 s.

Images were acquired using a 3-T whole-body MRI scanner (Achieva, Philips Medical Systems, Best, The Netherlands) with an eight-channel head coil. Head motions were minimized with a forehead strap and comfortable padding around the participant’s head. For each participant, a T1-weighted anatomical image oriented parallel to the AC–PC was first acquired using a fast-field echo sequence (T1-FFE; TR = 253 ms, TE = 2.30 ms, flip angle = 80°, 38 axial slices, slice thickness = 4.50 mm, no interslice gap, FOV = 240 mm × 240 mm, matrix = 268 × 214, and acquisition voxel size = 0.43 mm × 0.43 mm × 4.5 mm). Parameters of acquisition were the same as in Carre et al. (35 (link)) conducted on the same machine. Functional data were acquired using an ascending slice acquisition 2D-T2*-weighted EPI sequence sensitive to BOLD contrast, in the same axial plane as the T1-weighted structural images (2D-T2*-FFE-EPI; EPI factor = 39, TR = 2,000 ms, TE = 30 ms, flip angle = 90°, 38 axial slices, slice thickness = 3 mm, no gap, matrix = 80 × 72, FOV = 240 mm × 216 mm, acquisition voxel size = 3 mm × 3 mm × 4.5 mm). The 560 functional volumes were collected during two consecutive functional sessions (total scan time = 18 min and 40 s).

Recordings were conducted in a magnetically-shielded room with active shielding engaged. With an acquisition bandwidth of 0.1–330 Hz, neuromagnetic responses were sampled continuously at 1 kHz using an Elekta MEG system with 306 magnetic sensors (Elekta, Helsinki, Finland). MEG data from each participant were individually-corrected for head motion and subjected to noise reduction using the signal space separation method with a temporal extension39 (link). Each participant’s MEG data were then coregistered with their structural T1-weighted MRI data using BESA MRI (Version 2.0; BESA GmbH, Gräfelfing, Germany). These neuroanatomic images were acquired with a Philips Achieva 3T X-series scanner using an eight-channel head coil and a 3D fast field echo sequence with the following parameters: TR: 8.09 ms; TE: 3.7 ms; field of view: 24 cm; matrix: 256 × 256; slice thickness: 1 mm with no gap; in-plane resolution: 0.9375 ×  0.9375 mm; sense factor: 1.5. The structural MRI volumes were aligned parallel to the anterior and posterior commissures and were transformed into standardized space after source imaging (i.e., beamforming)40 (link)41 (link).

Imaging was performed on a 3T MR system (Philips Healthcare, Best, The Netherlands) with an eight-channel head coil. High-spatial-resolution 3D T1-weighted images were acquired with a turbo field echo sequence in the sagittal plane with the following parameters: repetition time/echo time, 8.21/3.78 msec; inversion time, 1026 msec; flip angle, 8°; effective section thickness, 1.0 mm; slab thickness, 190 mm; matrix, 240 × 240; field of view, 240 × 240 mm; number of signals acquired, 1; scan duration, 5 min 23 sec. All scans resulted in 190 contiguous slices through the brain.
The imaging parameters for the pCASL experiments were as follows: single-shot gradient-echo echo planar imaging in combination with parallel imaging (sensitivity encoding factor 2.0); repetition time/echo time, 4200/8.56 msec; matrix, 64 × 64; field of view, 240 × 240 mm; in-plane resolution, 3.75 × 3.75 mm; 20 slices acquired in ascending order; slice thickness, 6 mm; slice gap, 1 mm; labeling duration, 1650 msec; post-labeling delay, 1525 msec. Forty pairs of control/label images were acquired and then averaged. The total scan duration was 5 min 44 sec. The echo planar imaging M0 images were separately obtained with the same geometry and imaging parameters as the pCASL without labeling.

Participants were scanned on one of two systems running the same software version: a 3.0 T Philips Achieva scanner with an eight channel head coil at Salford Royal Hospital or a separate 3.0 T Philips Achieva scanner with a 32 channel head coil at the Manchester Clinical Research Facility. Involuntary movements in participants were minimised using padding within the head coil.
Both scanners ran an identical MRI protocol. A DCE-MRI dynamic series of 160 3D T₁-weighted images [T₁ Fast Field Echo (T₁-FFE)] were acquired with a temporal resolution of 7.6 s, spatial resolution of 1.5 × 1.5 × 4 mm, and total duration of approximately 20 min. On the 8th dynamic, a gadolinium-based contrast agent (Dotarem) bolus was administered using a power injector. The volume administered was proportional to the weight of the subject with a dose of 0.1 mmol/kg.
Prior to the dynamic scan, a series of additional 3D T₁-FFE images were acquired at three flip angles (2, 5, and 10 degrees) in order to calculate a pre-contrast T₁ map using the variable flip angle method. A B₁ map was also collected in order to correct for B₁ field inhomogeneities.
In addition, a 1 mm isotropic 3D T₁-weighted image and a T₂-weighted fluid attenuation inversion recovery (FLAIR) image were acquired. Please see supplementary material for full details of acquisition parameters.