Achieva quasar tx

Imaging was performed using a 3.0 T MRI scanner (Achieva Quasar TX; Philips Medical Systems, Best, the Netherlands) and 32-channel head coil (Sense Head Coil; Philips Medical Systems, Best, the Netherlands). T1-weighted whole-head structural imaging was performed using sagittal three-dimensional magnetization-prepared rapid acquisition gradient echo (MP-RAGE) with TR/TE 9.9/4.6ms; 240 mm² FOV; 240×240 matrix; partition thickness, 1 mm; and parallel acceleration factor 2.0. In addition, a 3D T2-weighted fluid-attenuated inversion recovery (T2W-FLAIR) acquisition was obtained with the following pulse sequence parameters: TR/TE/TI 11000/120/2800ms; 240 × 240 mm FOV; 240 × 240 matrix; 1mm partition thickness and parallel acceleration factor 2.0.

Imaging was performed using a 3.0 T MRI scanner (Achieva Quasar TX; Philips Medical Systems, Best, the Netherlands) and 32-channel head coil (Sense Head Coil; Philips Medical Systems, Best, the Netherlands). T1-weighted whole-head structural imaging was performed using sagittal three-dimensional magnetization-prepared rapid acquisition gradient echo (TFE- turbo field echo) with TR/TE 9.9/4.6 ms; 240 mm² FOV; 240×240 matrix; partition thickness, 1 mm; and parallel acceleration factor 2.0. In addition, a 3D T2-weighted fluid-attenuated inversion recovery (T2W-FLAIR) acquisition was obtained with the following pulse sequence parameters: TR/TE/TI 11000/120/2800 ms; 240×240 mm FOV; 240×240 matrix; 1 mm partition thickness and parallel acceleration factor 2.0. Diffusion tensor MRI employed a single shot spin-echo echoplanar acquisition with TR/TE 3000/65 ms; 256×240 mm FOV; 128×117 matrix; mm slice thickness with no gap; parallel acceleration factor 2.8, b value=800 and 32 diffusion sensitizing directions.

Images were first acquired at the Gruss Magnetic Resonance Research Center in Bronx (CCMA and EAS cohorts) or University of Angers Hospital in Angers (GAIT cohort), and then sent to Albert Einstein College of Medicine (Bronx, NY, USA) for pre-processing and group-level covariance analyses. The French images were acquired with a Magnetom Avanto 1.5T MRI scanner (Siemens Medical Solutions, Erlangen, Germany) and the American images were acquired with a Philips 3T MRI scanner (Achieva Quasar TX; Philips Medical Systems, Best, Netherlands). Standard three-dimensional T1-weighted images were obtained from all three cohorts: 1) CCMA: TR/TE of 99/4.6 ms., 240 mm² FOV, 240 × 240 × 240 matrix and 1 mm voxel size [for additional acquisition details see (Blumen, 2014 )], 2) EAS: TR/TE of 9.9/4.6 ms., 240 mm² FOV, 240 × 240 × 220 matrix and 1 mm voxel size [for additional acquisition details see (Ezzati et al., 2015 (link))], and 3) GAIT: TR/TE 2170/4.07 ms., 240 mm² mm FOV, 256 × 256 × 144 matrix and 1 mm voxel size [for additional acquisition details see (Beauchet et al., 2016a (link))].

Imaging was performed using a 3.0 T MRI scanner (Achieva Quasar TX; Philips Medical Systems, Best, the Netherlands) with a 32-channel head coil (Sense Head Coil; Philips Medical Systems). Details of the imaging protocol has been described previously (Ezzati et al., 2014 (link)). Tl-weighted volumetric images were processed using the FreeSurfer software package (version 5.3, available at FreeSurfer Developer website). For each subject the estimated total intracranial volume (TICV) and the whole hippocampal formation on each side was estimated using Free Surfer’s standard segmentation procedure using a probabilistic brain atlas (Fischl et al., 2002 (link)). Details of MRI analysis has been described previously (Ezzati et al., 2014 (link)).