Magnetic Resonance Research Center Facility and Resources
The MR Research Center (MRRC) is a state of the art facility located on the 8th floor of Presbyterian University Hospital supporting an MR Research Program that includes 14 faculty and 14 support staff. The Program is built around development and application of acquisition and image reconstruction schemes for clinical as well as research MRI studies. The Center opened September 1994. The center has access to medical support facilities and staff. All scanners are equipped with MRI-compatible cardiac EKG equipment and blood oxygen monitors. The scanners are operated by registered MR Technologists. PALS-certified registered nursing personnel perform research subject safety screening and preparation.
A Siemen's Biograph mMR (PET/MR) scanner became operational in the Fall of 2012 at the MR Research Center. This state-of-the-art whole-body human scanner integrates a 3T Verio MRI and PET scanner. The mMR can acquire simultaneous MR and PET images with the quality of separate PET and MRI scanners. This optimized design incorporates low-attenuation materials into the mMR coils to minimize attenuation of the PET signals, resulting in outstanding 3T MRI performance and a high-resolution PET exam. The system is equipped with an fMRI paradigm presentation system for functional studies. The system can perform 1H spectroscopy but is not currently capable of multinuclear MR spectroscopy.
The MR Research Center also houses three Siemens Medical Systems 3 Tesla Magnetom TIM Trio scanners. TIM, Total Imaging Matrix, is an innovative RF system and coil design that allows for whole body scanning without coil changes and subject repositioning. These systems are dedicated to research studies, primarily focused on the development of functional MRI, investigation of novel contrast mechanisms, and applications in Neuroscience, Psychology, and Neurosurgery.
The magnet rooms are magnetically, acoustically and RF shielded. The compact superconducting magnet (198cm or 6’ 6” long) can accommodate a 50cm field of view and has excellent homogeneity, typically 1.2 ppm, based on 24 plane plt, 50cm Diameter Sphere Volume. The Audiocomfort feature combines hardware and software to reduce acoustic noise up to 20 dB (A) compared to conventional 3T systems. The system has a top of the line gradient system with 45mT/m maximum amplitude, and a slew rate of 200T/m/sec with a 100% duty cycle. It also includes up to 102 seamlessly integrated coil elements with up to 32 RF channels and PAT up to 16. All conventional and echo planar MR imaging and MR angiographic functions (both phase contrast and time-of-flight methods) are supported. Two of the scanners operate under version VB15 software that provides multi-nuclear capabilities not previously available under the TIM platform. The third scanner was recently upgraded to the TIM platform with version VB17 software and is dedicated to the Osteoarthritis Initiative, or OAI, a multicenter, longitudinal, prospective observational study of knee osteoarthritis (OA).
A fourth scanner is housed in the basement of the Biomedical Science Tower, located within walking distance of the MRRC. This 7T system is a Siemens retrofit of a GE magnet. As part of this retrofit, the scanner was upgraded to 32 independent receive channels, each of them with multi-nuclear capabilities. A set of parallel imaging coils (12 channels) for sodium and lithium imaging are available on this scanner. To achieve high slew rate, the scanner is fitted with a head only, removable, gradient set capable of 80mT/m gradients and 800mT/m/s slew rate. Finally, the 7T supports parallel transmission capabilities with the addition of a parallel transmission unit from Siemens Medical Systems. This unit provides 8 independent transmission channels as well as support for additional gradient controllers that could be used for dynamic shimming applications. All these development activities are supported onsite by a system engineer from Siemens Medical Systems and MR faculty with expertise in MRI hardware.
A 12-channel receiver array head-coil for parallel imaging capabilities is available on both 3T systems, as well as neck, spine and body matrix coils and a shoulder, extremity, 8 channel knee and breast array coils.
Mock Scanner/MRI Simulator
The Center houses a mock MRI scanner that can be used to acclimate adults and children to the MRI scanner environment. The mock scanner includes a mock head coil, Motrak head motion monitoring system that tracks participant movement during a simulated scan, and a computer running Eprime software for visual and auditory stimulus presentation and recording of subject feedback.
Two of the 3.0T scanners are fitted with MRI-compatible eye tracking monitoring and recording systems (ASL, Bedford, Massachusetts) The EYE-TRAC®
6 series uses optics that provide optimum pupil image contrast in most indoor environments. The systems include control units with long-range remote optics and multi-speed camera with telephoto lens needed for the MRI environment, two 9 inch black and white monitors, one 5 inch LCD monitor for the MRI scan room, and the EYEPOS package for real-time conversion of the eye movements into numerical pupil position and diameter data streams. The system includes a custom PC with two frame grabbers, one capable of supporting 240 Hz eye imaging, and the other capable of recording to disk the entire image of the eye during the MRI scan.
Physiological Monitoring Equipment
A Veris MR compatible physiological monitor (MEDRAD, Indianola, PA), is available with one of the 3T scanners. The system includes a variety of blood pressure cuff sizes, flexible grip pulse oximeter probes, two channels of skin surface temperature utilizing fiber optic technology and is capable of analyzing mixed gases and anesthetic agents.
Brain Products EEG-fMRI
Due to the generosity of The BrainAmp MR is a shielded amplifier which can be taken directly inside the MRI chamber and placed right behind the subject’s head. From the amplifier the digitized signal is sent via fiber optic cable to the USB interface located in the control room. Therefore no artifacts can be added along the way to outside of the MRI chamber. The short length required for the electrical cables used to connect the electrode cap with the amplifier complies with all safety requirements for the experimental subject.
The sturdy and compact BrainAmp MR, which is powered by the rechargeable battery PowerPack, can be stacked one on one to acquire up to 128 EEG channels with ease.
The BrainAmp MR can be combined with the MR compatible ExG amplifiers to add the capability to record bipolar and peripheral signals (e.g. EOG, ECG, EMG, GSR - Galvanic Skin Response, etc.) in an extremely compact setup.
Functional Imaging Stimulus Presentation Equipment
- Projection Screen with Stand: High resolution, magnet compatible.
- Projection Mirror with Stand: Heavy duty, magnet compatible mirror stand and optical grade front surface mirror.
- MRI compatible vision correction lens system with a variety of diopters
- BrainLogicsTM MR Digital Projection System uses Digital Light ProcessingTM (DLP) technology that provides microsecond rise times, outstanding contrast with all-digital fiber optic control, and color tracking technology that allows you to project crystal clear, sharp, images with repeatable precision from run to run and across laboratories. Visual presentation is central to most all fMRI experiments.
- Avotec Silent Scan audio system & headphones:
Communication console with gooseneck microphone and stethoscopic headset
AC power supply; DC power/signal cabling between console and transducer;
RF filter for penetration panel connection; two channel filter bank;
Scan-LockTM Plus research tubing assembly;
One-third octave (OTO);
Audio (output): Frequency response (typical): Flat response (+/-) 4dB 200-4500Hz; calibration points at 200, 500, 1000, 2000, 3000, 4000 Hz; time delay 9ms (nominal); non-dispersive acoustic propagation (constant phase delay).
- Fiber Optic Button Response System (includes the hand units and console)
The Fiber Optic Button Response Units attach to the participant's wrists and can be comfortably adjusted during scanning. The units are constructed almost entirely from plastic, completely eliminating all metal inside the magnet room. The units communicate button presses through fiber optic cabling which connects to a Fiber Optic Interface Console located in the control room through an available wave guide.
The Fiber Optic Interface Console provides real-time feedback of participant responses via LED indicators and includes a set of switches which can be used to make responses for the participant as needed. The system seamlessly integrates with E-Prime® through a serial connection and other software packages through a USB connection. TTL output signals can be used to interface with other data collection devices and software. The interface console comes with a BNC Connector that allows the computer to accept a TTL Pulse that the stimulus presentation computer interprets as another button press, allowing the user to synchronize their experiments with the MR scanner.
Urine Pregnancy Testing
Urine pregnancy testing is available if required by your IRB protocol. MRRC staff will administer this testing using the ICON 25hCG, Beckman Coulter, immunochemical test.
Computing, Networking And Data Transfer
Three independent, but interconnected, LAN's support the operation of the MRRC, a research network, an administrative network and a scanner network. The computational power for the research network is supplied by multiple server resources. These resources include an eight node linux CPU cluster providing 16 Intel Xeon E5-2690 2.90GHz Eight-Core Processors, 2 TB DDR3-1600 Reg ECC Memory and operating on 6Gb/s Interface Solid State Drives. Another resource is a linux GPU cluster with four Nvidia M2090 GPUs, two Intel Xeon E5-2667 2.90GHz Six-Core Processors, 256GB DDR3-1600 Reg ECC Memory and operating on 6Gb/s Interface Solid State Drives. The MRRC also utilizes a Linux cluster with four 2.0GHz dual-core Opterons. The Linux servers provide over 200TB of online data storage.
Access to the servers is performed through multiple Linux, Macintosh, and Windows workstations. The cluster resources are connected via InfiniBand Switch. All computers on the research network are interconnected by a 1Gb/s LAN. Commercial software for image analysis (AVS, SAGE, IDL, Analyze, MATLAB) as well as freeware packages (FSL, SPM, MIPAV) complements the development of customized software for individual projects.
The scanner network operates on a combination of thin-wire Ethernet and 1Gb/s switched router. This network provides low latency access to all computers supporting the different subsystems for the various MR scanners and is connected through a router to the research and administrative networks.
MRRC defined quality assurance procedures are in place for all scanners. These include daily signal stability scans for echo planar imaging (1% maximum RMS over a continuous 30 minute acquisition with a 64x64 matrix size) and daily signal-to-noise measurements with the standard RF head coil. One of the 3T Scanners is accredited by the American College of Radiology. The MR Research Center has maintenance agreements with the scanner manufacturers that guarantee service in less than 12 hours whenever daily stability scans fail to meet the required specifications.