4.7 T RESEARCH MAGNET : This lab contains a radio-frequency and magnet shielded room in a contiguous lab supporting human and rodent MR spectroscopy, including physiological monitoring equipment. The magnet is a special design horizontal Bruker short bore 30 cm instrument for which the sweet spot is just 17 inches from the front of the magnet, thus accommodating rodents and human limbs. New gradients were installed in 2010.

We upgraded through a S10 instrumentation grant (January 2015) to a Bruker MR console consisting of software, computer workstation, digital electronics, RF electronics and an MR volume coil. They come as a ‘turn-key’ package prepared by Bruker to match our 4.7T magnet. Dr. Eric Shankland, our Chief MR Scientist, has extensive experience with Bruker high-resolution systems running on the 4.7T console and the nearly identical console on the 14T MR system for mouse MRS. Thus, we have two MRS systems with identical state-of- the-art electronics (consoles), each having specific advantages for the measurements proposed here. The 4.7T magnet is a wide, horizontal bore magnet (>20 cm diam with gradients) that accommodates rats.

MUSCLE FATIGUE TESTING : We have a small LabView data acquisition hardware and software (muscle force, EMG, respiration rate) and dedicated computer.

ANIMAL MONITORING SYSTEM:  We have a Small Animal Instrumentation, Inc. Model 1030 monitoring and gating system. It provides a continuous monitor of animal physiologic status while generating gate signals to synchronize scanner data acquisition with cardiac and respiratory motion. MR-compatible heater and ventilator options are available to control the temperature and ventilation of mice and rats during MR or other imaging procedures. It is a 3rd generation system designed specifically to meet the physiological monitoring and gating needs for anesthetized mice, rats and larger animals in the MR environment. The system consists of an ERT Module located near the animal in the magnet bore and an ERT Control/Gating Module connected to a PC located near the operator console. The PC displays multiple waveforms, measured values, trends and gating pulses.

• The ERT Module measures ECG using three leads with needle or surface electrodes, respiration from a small pneumatic pillow sensor and/or from the movement of one ECG lead in the strong magnetic field and temperature with a small rectal thermister probe. Power is supplied by an external, rechargeable battery. The
• ERT Control/Gating Module receives data from the ERT Module and any of several optional acquisition modules. The ERT Control/Gating Module sends data to the PC for display and receives user instructions from the PC to control measurement and gating functions. Gates from ECG, respiration and any of the available options are generated by the ERT Control/Gating Module’s microprocessor and sent to the MR system. The delay from the R-wave peak to the MR system gate is user selectable as is the expiration gate delay and width. The module also controls a heating system which can regulate the temperature of the animal.

BODY VOLUME COIL:  We upgraded the 4.7T magnet with the gradient and shim coils and power supplied with a customized apparatus supported by a Shared Instrument Grant awarded Feb 2006. The essential features of this new apparatus are given in the Table below. We re-designed the apparatus so that human legs can be positioned appropriately. Fig A gives a diagram for the new custom gradients. The front of the magnet is on the left. The novelty of this gradient is that the actual space for the gradient coils occupies only the middle part of the bore. On the front end, the ID is 26 cm, a diameter that is comfortable for most of our human subjects. The 20 cm ID will begin at the lower thigh. At the back of the magnet, sectors are cut out to allow the electrical and water connections on the horizontal plane, while the gradient shell material is cut out in sectors on the vertical plane allowing full 26 cm access needed for the ankle and foot positioning and comfort. This customized arrangement was constructed by Resonance Resources Inc.