Prismafit scanner

Participants undergo whole brain MRI on a Siemens 3 Tesla Prisma Fit Scanner with a 64-channel coil to collect 3D-T1 Magnetization Prepared Rapid Acquisition Gradient-Echo (MPRAGE) sequences (1.0x1.0x1.0mm^{3 (link)}) and rs-fc scan at resting state with eyes open. We will calculate functional connectivity strength within networks from 2 six-minute blood oxygen level dependent (BOLD) rs-fc MRI scans wherein the participant is asked to rest quietly in the scanner with eyes open and without falling asleep. T-1 isometric structural scans are used for co-registration.^{50 (link),93 (link),94 (link)} The BOLD time-series will be extracted from a total of 36 previously defined seeds constituting the DMN and SAL networks as well as the dorsal attention (DAN), executive control (CON), and sensorimotor (SMN) networks.^{93 (link)} Relationships between each of the 36 seeds will be calculated by constructing 36x36 cross-correlation matrices and Fisher z-transforming the resulting correlation values.^{50 (link)} DMN and SAL data will be summarized as composite scores representing mean intra-network functional connectivity. A whole-brain analysis will then be performed on the entire matrix of pairwise relationships to explore treatment effects in other functional brain systems.

For this case study, the patient completed the following over the course of one month: a neurological consultation, a neuropsychological evaluation, and a brain MRI on a research-dedicated 3T Siemens Prisma^fit scanner with a 32-channel head coil, acquiring: T1-weighted magnetization-prepared rapid gradient-echo sequence, T2-weighted fluid attenuated inversion recovery sequence, T2-weighted susceptibility weighted imaging, DTI, and FBI. Total scan time was 1 hour and 50 seconds (see Supplementary Material for acquisition parameters and image analysis procedures). Her images were reviewed by a neuroradiologist, who had the patient’s scans from one, three, and six years prior for comparison.
Prior clinical and research data are also summarized here. Specifically, clinical evaluations from neurology, neuroradiology, and neuropsychology were reviewed from 6 years prior (when the participant was age 68), and neuropsychological test results from another research study was reviewed from 3 years prior (when the participant was 71) in which an author (A. B.) was the principal investigator. This case study was approved by the Institutional Review Board (IRB) at the Medical University of South Carolina. The control FBI data were obtained from a separate IRB-approved study. Both were compensated for their participation in research.

Before building a B₀ shim module to incorporate into the automated protocol, three different B₀ shim techniques were compared: Siemens-provided Advanced shim (double-echo steady state sequence (12 )) and “Brain” mode shim (gradient-echo sequence) and the FAST(EST)MAP (FM) protocol (13 (link)). Five healthy participants (32±10 years old, 4 females) gave informed consent approved by the University of Minnesota Institutional Review Board prior to the scan. Water signal was measured using sLASER (8 (link)) from six different VOIs on a 3T Siemens Prisma^fit scanner running Syngo VE11C. Water peaks were post-processed offline using MRspa (14 ): eddy-current corrected followed by measurement of their linewidth.