Intera achieva scanner

Imaging for both studies was performed on the same 3 T Philips Intera Achieva scanner. The imaging protocol was the same in both studies except for a different resolution of the structural scans. Structural images were acquired with a magnetization prepared rapid gradient echo (MPRAGE) sequence, sagittal acquisition, echo time 4.6 ms, repetition time 8.3 ms, inversion time 1250 ms, flip angle = 8°, SENSE factor = 2, and in-plane field of view 256 × 256 mm² with slice thickness 1.2 mm, yielding a voxel size of 0.93 × 0.93 × 1.2 mm³ (study 1) and in-plane field of view 240 × 240 mm² with slice thickness 1.0 mm, yielding a voxel size of 1.0 × 1.0 × 1.0 mm³ (study 2). Resting state scans were obtained with a gradient echo echo-planar imaging sequence with 25 contiguous axial slices, 128 volumes, anterior-posterior acquisition, in plane resolution = 2.0 × 2.0 mm, slice thickness = 6 mm, repetition time (TR) = 3000 ms, echo time = 40 ms, and field of view = 260 × 260 mm². Participants were asked to keep their eyes open and stay awake for the duration of the resting state scan. DLB patients who were taking dopaminergic medication were scanned in the ON state.

All images were collected using a 3 T Philips Intera Achieva scanner (Amsterdam, Netherlands). Three-dimensional, high-resolution T1-weighted images were collected using a magnetization-prepared rapid gradient-echo sequence. The parameters were as follows: 240 × 240 × 162 matrix, time repetition (TR) = 6.5 ms, time echo (TE) = 3 ms, time to inversion (TI) = 711 ms, field of view (FOV) = 24 cm, 162 slices, and 1.0-mm slice thickness (voxel size: 1.0 × 1.0 × 1.0 mm³). The scan duration was 8 min and 3 s. First, we checked the T1 image by visual on-site inspection; when obvious motion artifacts were found, the T1 image was scanned again immediately, and the re-scanned image was used for further analyses.

All brain images were acquired using a 3-T Intera Achieva scanner (Phillips Medical Systems, Best, The Netherlands) at time point 1. T1WIs were collected using a three-dimensional, high-resolution, magnetization-prepared rapid gradient echo sequence. The imaging parameters were as follows: 240 × 240 matrix, TR = 6.5 ms, TE = 3 ms, TI = 711 ms, FOV = 24 cm, 162 slices, 1.0-mm slice thickness, and a scan duration of 483 s. Although our participants were children, sedation was not administered. Participant body motion was carefully observed by the technical staff during image aqcuisition. Scanning was repeated in the cases of excessive movement. The quality of the obtained images was evaluated by a professional radiologist (YT). Images with motion artifacts were excluded from analysis.

All MRI data were acquired with a 3-T Philips Intera Achieva scanner. The diffusion-weighted data were acquired using a spin-echo echo-planar imaging (EPI) sequence (TR = 10,293 ms, TE = 55 ms, big delta (Δ) = 26.3 ms, little delta (δ) = 12.2 ms, FOV = 22.4 cm, 2×2×2 mm³ voxels, 60 slices, SENSE reduction factor = 2, number of acquisitions = 1). The diffusion weighting was isotropically distributed along 32 directions (b value = 1,000 s/mm²). Additionally, a dataset with no diffusion weighting (b value = 0 s/mm²; b0 image) was acquired. The total scan time was 7 min 17 s. Then, FA values were calculated from the collected images. This information is of particular interest when making inferences regarding white matter microstructural properties, as diffusion is faster along axons than in the perpendicular direction. Consequently, diffusion in white matter is anisotropic (i.e., diffusion rates in different directions are unequal). By contrast, isotropic diffusion is equally fast in all directions. FA in each voxel was used as a measure of the degree of diffusion anisotropy. FA varies between 0 and 1, with 0 representing isotropic diffusion and 1 representing diffusion occurring entirely in one direction. After DTI image acquisition, FA map were calculated from DTI data using the software that was pre-installed on the Philips MR console.