8 channel receive only head coil

Scanning took place at the Newcastle University Magnetic Resonance Centre. A 3 T Philips Intera Acheiva MR scanner acquired anatomical T1-weighted images and functional T2^∗-weighted echo planar images (EPIs) using a Philips 8-channel receive-only head coil. The high- resolution T1-weighted scan contained 150 slices with an acquisition time of approximately 5 min. The structural scan parameters were: repetition time (TR) = 9.6 ms, echo time (TE) = 4.6 ms, flip angle = 8°. The field of view (FOV) was 240 mm × 240 mm × 180 mm with a matrix size of 208 × 208 pixels. Each voxel was 0.94 mm × 0.94 mm × 1.2 mm in size. The T2^∗-weighted EPIs were acquired from the bottom to the top of the head and comprised of 29 axial slices. The parameters of the EPIs were: acquisition time (TA) = 1.3 s, TR = 1.92 s, TE = 40 ms, flip angle = 90°. The FOV had a matrix size of 64 × 64 pixels and was 192 mm × 115 mm × 192 mm. Each voxel was 3 mm × 3 mm × 3 mm in size. There was a 1.0 mm gap between slices. To increase the signal-to-noise ratio of the functional images, sensitivity encoding (SENSE) was used with factor = 2. For each run, a total of 160 functional images were acquired (319 s). Four “dummy” scans were acquired prior to each functional run to allow for equilibration of the T1 signal.

Each site used a 3T scanner (Philips Achieva; Philips Healthcare, Best, the Netherlands) with an 8-channel receive-only head coil and used the same scan protocol. Participants were placed head-first supine with legs slightly elevated for comfort when desired. A parent or guardian could remain with them in the scanner room. Earplugs and headphones were used to dampen the noise of the scans and to communicate with and motivate the participants between scans. Music of the participants’ choice was played over the headphones during the anatomical scans. During the resting-state fMRI scan participants were instructed to keep their eyes open (without fixation) to prevent them from falling asleep and the music was switched off.
A three-dimensional T1-weighted scan (T1w; echo time (TE) = 4.6 ms, repetition time (TR) = 9.8 ms, spatial resolution (SR) = 1.17 × 0.92 × 1.2 mm, 140 slices, flip angle = 8 degrees, 4:55 minutes) was acquired for anatomical reference. A resting-state functional BOLD scan (RS-fMRI; FEEPI, TE/TR = 30 ms / 2200 ms, SR = 2.75 × 2.75 × 2.72 mm, 160 dynamics, 38 slices, flip angle = 80 degrees, EPI factor = 29, SPIR fat suppression, 6:01 min) was made to assess the functional connectivity.

Brain imaging was carried out on a 3 Tesla Philips Achieva MR system (Philips Medical Systems, Best, The Netherlands) equipped with gradient strength 80 mT/m and slew rate 200 T/m/s using an 8-channel receive-only head coil at the Centre for Advanced Medical Imaging, St. James’s Hospital, Dublin, Ireland.

Magnetic resonance (MR) data were acquired on a 3 Tesla Philips Achieva system using an 8-channel receive-only head coil. T1-weighted images were acquired using a 3D volumetric fast gradient echo sequence with, spatial resolution = 1 × 1 × 1 mm³, field-of-view (FOV) of 240 × 240 × 163 mm, TR/TE = 25/2.1 ms, flip angle = 30°, SENSE factor = 2. Following file conversions and quality assessments, T1-weighted structural data were analyzed for 31 MS patients and 18 healthy controls. The parameters for fluid attenuated inversion recovery (FLAIR) imaging were the following: TR/TE, 11000/125 ms; TI: 2,800 ms; turbo factor: 31; refocusing angle; 120°; spatial resolution: 0.5 × 0.5 × 4 mm; SENSE: no. Diffusion tensor images (DTI) were acquired using a spin-echo planar imaging (SE-EPI) sequence with a 32-direction Stejskal-Tanner diffusion encoding scheme: FOV = 140 × 244 × 244 mm, 70 slices with no inter-slice gap, spatial resolution = 2 × 2 × 2 mm³, TR/TE = 12285/55 ms, SENSE factor = 2, b-values = 0, 1000 s/mm², with SPIR fat suppression and dynamic stabilization in an acquisition time of 8 min 16 s. Following file conversions and quality assessments, diffusion tensor data was pre-processed for 22 MS patients and 19 healthy controls.