University of Nebraska Medical Center

Neuroimaging Core

Magnetic Resonance Imaging (MRI)
The CoNDA Center oversees a new research-dedicated 3-Tesla Siemens Prisma MRI scanner, equipped with 20-, 32-, and 64-channel head coils, as well as other coils for cardiac, spinal, and other types of imaging. The instrument is configured with multiband imaging capabilities and many experimental, research-only, and commercial sequences, including numerous MRI sequences for advanced diffusion, spectroscopy, structural, and functional brain imaging. The system has the [204×64] XR 80/200 gradients (the most powerful commercially available gradients). The Prisma MRI Suite is also equipped with the necessary peripherals to present experimental stimuli and acquire behavioral responses, including a 32” in-room LCD monitor for presenting stimuli and multiple ergonomic subject response devices.

Brain Stimulation
The CoNDA Center is also equipped with state-of-the-art electrical brain stimulation equipment, including three Soterix Medical systems. The suite includes a standard two-pad tDCS system, a two-pad transcranial electrical stimulation (tES) system, a five-lead multipolar high-definition tDCS system (HD-tDCS), and a five-lead alternating-current stimulation (tACS) system. All of the systems are equipped with settings for sham-stimulation, which allows investigators to use “placebo-controlled” experimental designs. In addition to the stimulators, there is a Polhemus digitizer for coregistering the stimulation sponges or metal electrodes to neuroanatomical images. Users also have access to advanced software for finite-element modeling (FEM) of current flow using the participant’s individual anatomy.

Magnetoencephalography (MEG)
Our facility houses a state –of the art a 306-channel whole-head MEG system (TRIUX, Neo, MEGin) and 128 channels -EEG amplifier.MEG helmet does coverage for whole cortex, 1220 cm2. MEG system has three measurement positions:supine, lower and upper seated. MEG sensors are divided into two types: 102 identical plug-in triple sensors units with two orthogonal planner gradiometers flux transformers, one magnetometer flux transformer and three dc-SQUIDs (Super-conducting QuantumInterference Devices). Size of gradiometers is 28mm x 28 mm, size of magnetometers is 21 mm x 21 mm. The MEG system is housed within magnetic shielded room (MSR) equipped with active shielding and automated helium recycler. The electronics comprises 306 MEG channels, 12 bioamplifier channels (SAM) and 128 EEG channels. Both MEG and EEG can be recorded simultaneously, with analog high-pass filter cut-offs dc/ 0.03 Hz /0.1 Hz/ 10 Hz (-3dB corner frequency), selectable individually for each channel by software. Low passfiltering by data acquisition software. MEG system is equipped with stimulation systems (for auditory, visual, motor and sensory tasks and intercom option with microphone). For the task–related response, we have non-magnetic single-fingeroptical response pad: finger-press more, finger-lift more and trigger output. For visual stimulation, we have high -fidelity video projection system, three -panel DLP video projector, 1,400 x 1,050-pixelnative resolution, 16-bit color depth, 112 cm screen on wheels. For auditory stimulation we have non-magnetic tubal-insert earphone set, independent delivery of auditory stimuli to each ear, 80 dB pressure level, >50 dB channel separation, <1 ms jitter between triggers and stimulus onset.3D digitizer (Polhemus Fastrack) is used for the head shape recordings. For subjects/patient support, the MEG lab is equipped with subject chair, subject bed and pediatric chair. Data analysis can be performed on three LINUX workstations.

Data Processing
The CoNDA Center includes a high-performance computing space. This space currently includes over 50 high-performance workstations for data processing, a 36 terabyte (RAID5) storage array for MEG and MRI data and a video conferencing system for virtual meetings. Each computer has Matlab and other important software for neuroimaging and statistical analyses, including many packages such as SPM, FSL, AFNI, FreeSurfer, CONN, R and other leading toolboxes. Many of the computers are also equipped with the Brain Electrical Source Analysis (BESA) software, SPSS and current-distribution modeling software. The open concept space encourages collaborative programming (e.g., algorithm development), and data processing efforts among students and faculty.