32 channel phased array head coil

A 3 Tesla Philips MR System Ingenia scanner with echo planar capability (Release 4.1 Level 3 2013-04-05, Philips Medical Systems Nederland B.V.) and a 32-channel phased array head coil was used for imaging. Subjects had to wear ear plugs and headphones for noise protection. We also used cushions in the coil to minimize head movement. A T1-weighted high-resolution 3D data set was acquired for each subject for anatomical referencing. Functional MR data were acquired using an EPI sequence in the identical position as the anatomical images [Field of View: 230 mm × 230 mm × 132 mm; spatial resolution: 3 mm × 3 mm × 4 mm; slice thickness: 4 mm; gap: 0.15 mm; repetition time: 2000 ms; echo time (TE): 35 ms; 25 axial slices].
The results of the resting state sequence will be presented elsewhere (Keeser et al., unpublished).

A Philips Achieva 3.0T MRI scanner (Philips, Best, Netherlands) with a 32-channel phased-array head coil was used to collect the 3D T1-weighted images. All subjects were in a supine position with their heads still and eyes closed. Memory pads and earplugs were used to reduce motion artifacts and scanning noise, respectively. The MRI scan parameters include: sagittal scan, repetition time (TR) = 7.1 ms, echo time (TE) = 3.5 ms, acquisition matrix size = 220 × 199, reconstruction matrix size = 352 × 352, flip angle = 8°, the field of view (FOV) = 220 mm², slice thickness = 1.0 mm, slice gap = 0 mm, and slice number = 155.

All children underwent a half-hour whole-brain MRI scanning protocol, using the same scanner (3T Philips Achieva, 32-channel phased-array head coil). To avoid subject motion, children were familiarized with the scanner prior to entering the scanner room, were repeatedly encouraged not to move and a movie was presented during all non-functional images. Multiple MRI modalities were acquired: T2-weighted fluid-attenuated inversion recovery images (T2-FLAIR, resolution = 0.68 × 0.68 × 4 mm, 1 mm slice gap, TR/TE/TI = 9000/120/2500 ms, FA = 90°, FOV = 230 × 139 × 187 mm), high-resolution T1-weighted images (MPRAGE, resolution = .98x.98 × 1.2 mm, TR/TE = 9.6/4.6 ms, FA = 8°, FOV=160 × 256 × 256 mm), multi-shell diffusion-weighted images (b-value = 0/700/2000 s/mm² with respectively 6/30/60 uniformly distributed gradient directions, resolution = 2.5 × 2.5 × 2.5 mm, FOV = 240 × 240 × 125 mm, TR/TE = 7000/72 ms, FA = 90°, Phase encoding = AP, halfscan = 0.766, one additional b0 image with reversed phase-encoding) and resting-state functional images (rs-fMRI, using T2*-weighted Echo-planar imaging, resolution = 3.59 × 3.59 × 4 mm, FOV = 230 × 230 × 120 mm, FA = 90°, TE/TR = 33/1700 ms, acquisition time = 7 min, 250 vol + 4 initial dummy volumes).

Imaging was performed on a 3 Tesla magnet (Philips, Achieva, Andover, Massachusetts) using a 32-channel phased array head coil. The following sequences were performed for each patient: Structural Imaging: T1-weighted, three-dimensional volume acquisition fast field echo (TR/TE: 7.2/2.9 ms, flip angle: 7 degrees, TI: 1100 ms, voxel size: 0.9 x 0.9 x 0.9 mm³); Functional Imaging: Single-shot echo planar blood oxygenation level dependent images (TR/TE: 2000/30 ms, flip angle: 80^o, voxel size: 3 x 3 x 3.75 mm³). Functional images were acquired in the resting state for 10 minutes (300 volumes) for each patient. Patients were instructed to lie quietly in the scanner with their eyes closed. All images were visually inspected for artifacts, including susceptibility and subject motion.