MRI image


The current MRI scanner is an ultrahigh performance 3 Tesla (3T) GE MAGNUS scanner with peak gradient amplitude 300mT/m and maximum gradient slew rate of 750 T/m/s and has 64 high-bandwidth receive channels for improved multi-coil signal detection.  The MAGNUS purchase was partially supported an NIH S10 (OD030415) High End Instrumentation grant and was installed in mid-2023.  Receiver coils include a 32 channel head coil (Nova Medical) and an 8 channel array for nonhuman primate imaging (Clinical MR Solutions).  The scanner has the ability to run in research mode, allowing modified research sequences both from in-house and external collaborators to be used in addition to the standard GE pulses sequences already provided.   The core maintains a library of custom sequences designed by BIC scientists to provide new features not available on the vendor supplied software and to maintain stability across vendor-forced software-platform upgrades. Real-time AFNI is used to monitor head motion in real-time.  Synchronization and triggering signals are logged with BIOPAC.  The MAGNUS will provide extremely advanced neuroimaging capabilities with higher spatial resolution, faster scanning, less distortion, and increased diffusion-weighting capabilities.  The MAGNUS system will be installed at three sites by the end of 2023.

Stimulus presentation can be delivered by a high resolution back-projection system (VPixx). The VPIxx system uses a high refresh rate DLP projector (480Hz in color, 1,440Hz in grayscale and 10kHz for binary images). DLP permits extremely fast access and transmission of video, in microseconds. The VPixx system can also display in stereoscopic vision up to 400Hz with circular polarizing filter and passive glasses.

DTIMRI auditory stimuli are presented using a set of electro-dynamic headphones (MR CONFON), or OptoAcoustics OptoActive system.  The Optoactive system minimizes gradient noise both actively and passively and includes a noise cancelling microphone for recordings.  Both MR CONFON and OptoAcoustic systems are low profile and can be used with the head coil.   MRI sound levels are reduced in studies of sleeping young children using an acoustic foam insert.  Stabilizing patients to minimize head movement is critical for MRI studies.  With technician training, the BIC has successfully utilized foam inserts on all age groups.

Collection of peripheral, physiological measures in the MRI are done using the BIOPAC MP150 system. The MP150 system provides high resolution (16 bit), variable sample rates for analog and calculation channels, 16 analog inputs and two analog outputs, digital I/O lines (automatically control other TTL level equipment), and 16 online calculation channels. The MP150 system also enables high-speed acquisition (400 kHz aggregate) via an Ethernet connection to a host computer.

Electrodermal activity is acquired in the MRI scanner using the BIOPAC EDA100C amplifier and two 6mm Ag-AgCL non-polarizable electrodes placed either on the tips of the second and third fingers or on the thenar and hypothenar eminences of the palm, depending on the requirements and placement restrictions of individual studies.

Electrocardiogram activity is acquired in the MRI using the BIOPAC ECG100C amplifier and three Ag-AgCl lead electrodes, using Einthoven’s triangle potential measurement strategy. Blood oxygen saturation level and pulse plethysmogram data are acquired in the MRI using the BIOPAC OXY100C amplifier and a TSD124 transmitting LED / receiving photodiode module.  The amplifier transmits two wavelengths of light via LEDs through a pulsating vascular bed (finger) to the photodiode.

Skin temperature is acquired in the MRI using the BIOPAC SKT100C amplifier and a TSD202 thermistor transducer.  This amplifier includes a lower frequency response selection switch that permits either absolute (DC) or relative (via a 0.05 high pass filter) temperature measurement.

Carbon dioxide gas analysis is performed in the MRI using the BIOPAC CO2100C amplifier and AFT31-MRI gas sampling interface kit and disposable nasal cannulas.  This amplifier records varying end-tidal carbon dioxide concentration levels employing a single beam infrared, single wavelength, measurement technique.

Respiration data is acquired in the MRI using two BIOPAC RSP100C amplifiers and TSD201 respiration transducers to measure abdominal and/or thoracic expansion and contraction.

Blood pressure is collected in the MRI using Magmedix’s non-invasive Tesla blood pressure manometer.  Diastolic, mean, and heart rate can be acquired.  This monitor can be used on neonates, pediatric, and adult subjects (Adults:  Heart Rate: 30-220 BPM, Systolic NBP: 40-260 mmHg, Mean NBP: 20-200 mmHg, Diastolic NBP: 20-200 mmHg, Static Cuff Accuracy +/- 3mmHg).

Additionally, respiration and pulse oximetry data collected by the scanner can be acquired via a serial interface.