3t tim trio mri

Data were collected at three sites starting in 2014. The Centre for Addiction and Mental Health (CMH) in Toronto used a General Electric 750w Discovery 3T MRI throughout the study. Maryland Psychiatric Research Center started data collection using a Siemens Tim Trio 3T MRI (this MRI will be referred to as MRC) in 2014-15, and then upgraded to a Siemens PRISMA 3T MRI in 2016 (referred to as MRP). Zucker Hillside Hospital in New York started data collection using a General Electric 750 Signa 3T MRI in 2014 and 2015 (referred to as ZHH), and then upgraded to a Siemens PRISMA 3T MRI in 2016 (referred to as ZHP). Scans were labeled by site tag and scanning year. As scans were collected annually, we used the following terminology: ‘Year1’ is study initiation (fall of 2014), ‘Year2’ is the fall of 2015, and ‘Year3’ is the fall of 2016. Thus, for example, CMH_Year1 was a scan at the CMH scanner at study initiation, MRC_Year2 was a scan at the beginning of the second year on the original scanner at the MRC site, and ZHP_Year3 was a scan at beginning of the third year on that site’s upgraded scanner. Scans were performed at CMH for years one, two and three, on the ZHH and MRC scanner for years one and two, and at ZHP and MRP scanners for year three only. See Table 1 for study scanning flow.

Scans were acquired on a Siemens 3T Tim Trio MRI scanner, including T1-weighted and T2-weighted images. To determine regional brain volumes, we used the semi-automatic segmentation program Freesurfer (v5.3) using previously published techniques.^{23 (link)} Regional brain volumes, including the pons, were corrected for whole brain size to allow for comparison between patients.^{6 (link),17}

All 8 subjects had sagittally-acquired 3D T1-weighted magnetization-prepared rapid gradient echo (MPRAGE) sequences and 3D T2-weighted sampling perfection with application optimized contrast using different angle evolutions (SPACE) on a Siemens 3 T TIM Trio MRI scanner. A generalized autocalibrating partially parallel acquisition (GRAPPA) factor of 2 was used for both scans with 50 % phase oversampling for the MPRAGE and no oversampling for the SPACE sequences, as previously described by Glasser and Van Essen [22 (link)].

MRI data were acquired using a Siemens 3T TIM Trio MRI scanner (Siemens Healthcare, Erlangen, Germany) at Northwestern University’s Center for Translational Imaging (CTI). The following parameters were: 40 axial slices, thickness/ gap=3/3mm, TR/TE=2500/20ms, FA=80°, in-plane resolution=64×64, FOV=896mm×840mm, 244 volumes.