ARTS AND SCIENCES
Center for Cognitive and Behavioral Brain Imaging

Equipment

 

The Center for Cognitive and Behavioral Brain Imagingis housed in the basement of the Psychology Building and has a newly purchased Siemens 3T Trio magnetic resonance imaging Total Imaging Matrix (TIM) system with all the necessary ancillary equipment to carry out both structural and functional imaging studies.

TIM is a technology that allows for much faster scanning without reducing image quality and sacrificing spatial or temporal resolution. It also greatly improves statistical power of MRI and fMRI studies by increasing signal-to-noise ratio and reducing susceptibility artifacts. The Trio includes advanced MR gradient technology, including a high-performance 100%-duty-cycle shielded gradient coil (40mT/m) that exceeds previous standards, enhanced gradient amplifiers, 32-channel fast receiver modules, high-frequency broadband RF amplifiers, and passive/active shims for exquisite field homogeneity. The 60cm-diameter bore, 100% duty-cycle capability of the gradients, and the transmit/receive head RF coil make it ideal for human neuro-imaging applications within current FDA peripheral nerve stimulation guidelines.

 

The key attributes of the system are:

 

High field strength: High-field magnets have become the standard for functional MRI studies in basic research. They present major improvements that can be arbitrarily traded against each other: higher signal-to-noise ratio, high functional contrast-to-noise ratio, and faster scans. Both are critical for functional imaging, where neural signals last only milliseconds to seconds, and are weak compared to instrumentation noise.

 

Stable and proven design: The Trio is the latest of the Magnetom systems that are widely used in major research settings. Siemens has a track record of stability and reliability.

 

Comprehensive and versatile scan options: Some of the highlights of available scanning sequences include (also see a full list of features in Supplementary Documents):

 

  • Gradient-echo and spin-echo sequences (multi-planar or 3D) provide a wide range of tissue contrast (T1-, PD- and T2-weighted contrast) for structural imaging. With these sequences, MRI parameters (such as T1, T2, and proton density) can be quantified accurately.
  • Spin-echo sequences (multi-echo/multi-plane, inversion recovery and derivatives). These are particularly useful for automated tissue segmentation. They are ideally suited to the creation of a flat cortical map of each individual subject.
  • Fast spin-echo sequences (2D and 3D), which combine the advantages of spin echo techniques with higher resolution and faster acquisition times. This will allow us to acquire very high-resolution images (1024x1024), 3D datasets with cubic voxels, datasets with very thin slices through a combination of multiple interleaved 3D slabs, and also to perform flow compensation and magnetization transfer imaging.
  • Diffusion-weighted MRI can recover more anatomic substructure that cannot be resolved by conventional structural MRI methods. Diffusion tensor imaging (DTI) tractography allows the visualization of multiple white matter tracts based on diffusion tensor imaging data, and capture better visualizations of brain connectivity. DTI tractography in the system delivers up to 256 diffusion directions
  • Echo planar imaging (EPI) with a full database of pulse sequences for very rapid acquisitions will be ideally suited for functional MR imaging. Of particular interest here are the ultra-fast image reconstruction capability and real-time rendering packages running on the operator’s console. TIM was designed for excellent Parallel Imaging in all directions. It greatly improves contrast-to-noise ratio and spatial-temporal resolution, and minimizes image distortion in functional MR imaging.
  • Functional MRI imaging software package includes tools for visualization of the time course of a given voxel and creation of simple activation maps. Inline technology makes functional MRI solutions easier to perform, easier to interpret and easier to analyze. 3D PACE prospective motion correction are used for reducing the influence of head movement on functional MRI and improve the consistency of data.

The setup in the Center includes 12 channel and 32-channel phase array receiver head coils. Staffing includes a full time MRI physicist, a facility specialist, an MRI technologist, and a part-time Administrative Assistant. Behavioral responses can be recorded through a pair of fORP fiber optics-based button boxes, each with two buttons. BrainVoyager QX is available for users (up to four at a time) through a network. The configuration includes a state-of-the-art rear-projection system powered by a high-resolution SXGA+ (1400x1050) 3-chips DLP projector. The projector has a light engine with 13-bit intensity control per channel. This allows the presentation of subtle visual details near or below detection threshold. An EyeLink remote eye-tracker has also been installed and calibrated to monitor subject eye movement during fMRI scans. A HiFi MRI compatible auditory stimulus system and a high quality fiber optic speech recording system are also available to researchers.



Siemens MAGNETOM Prisma

3 T whole-body MR system

Coils

  • 32-channel head array coil
  • 20-channel head-neck matrix coil

Eyelink 1000 Eye Tracker

MR compatible monocular video-based eye tracker
  • Sampling rates: 250, 500, and 1000 Hz
  • Accuracy: 0.25-0.5 degrees average

Visual Stimulus Presentation System

Christie DS+6K-M 3-chip SXGA+ DLP projector
  • Native setting: 1280x1024 at 60Hz
  • Rear-projection screen: 55.1 pixels per visual degree
  • Display height: 24.0 cm
  • Viewing distance: 74 cm
  • Native gamma: 1.0 (linear)
  • 13-bit gamma table
  • Both Analog (VGA) and DVI input

MRI compatible HiFi audio auditory stimulus system

http://www.sens.com/s14/index.htm

MRI compatible speech recording system


MRI compatible Eyeglasses

  • Sphere lenses from +/-0.12 to +/- 20D
  • Cylinder lenses from +/-0.12 to +/- 6D
  • Prisms from 0.5 to 10D

Behavioral Response Box

fORP fiber-optics response pad: 2 sets of 2 buttons
Response Time Box

Mock Scanner

http://www.pstnet.com/hardware.cfm?ID=92
  • Identical bore dimensions as Siemens scanner
  • Mock Head Coil Siemens™ with Rear Facing Mirror System
  • SimFx software simulates the ambient scanner sound
  • MoTrak head motion tracking system
  • Response boxes