Stereotactic Device for MRI Team Members: Jeremy Glynn, Jeremy Schaefer, Mike Conrardy, Adam Goon Client: Ian Rowland, PhD Advisor: Prof. William L. Murphy Abstract Client Requirements Cannot interfere with imaging device (MRI compatible) Fit inside rat MRI coil (63 mm diameter) Brain centrally aligned down axis of MRI Anesthetic mask able to cover animals nose Complete restraint of animal’s head Withstand 4.7 Tesla magnetic field Heating device to warm animal  Maintain body temperature within 5 o of 37 o C Adjustable to accommodate various sized rats Motivation Rat positioned in restraint Final Design Testing Our design was implemented in the lab’s imaging procedure. Key improvements resulting from our design included: Rat was well-restrained, reducing motion artifacts Brain was properly aligned in all planes within the coil, producing level images. Proper alignment also decreased calibration time Anesthetic was appropriately delivered to the animalBackgroundReferences Budget Future Work MRI imaging done on rats is commonly used in neurological research. In order for the images to achieve high resolution and be valuable in research, it is crucial that the rat is well-restrained, the brain is centrally oriented within the coil, and the animal is kept warm while anesthetized. Problems with the current system include: Restraining Method: Tape Does not adequately secure the animal Makes proper brain alignment difficult Heating Method: Circulating Hot Air Heats the imaging coil, decreasing the signal-to- noise ratio (quality). Air flow blows anesthetic away from subject’s mouth. Figure 1: Rat and cradle being inserted into the MRI coil using the current restraint methods. Provide replacement pieces Replace hex screws with thumbscrews Run longer duration scans utilizing heating device Figure 2: Poor image resulting from improper alignment. Figure 3: Properly aligned image acquired using our prototype., [1] Benveniste, H. & Blackband, S. (August 2002). “MR microscopy and high resolution small animal MRI: applications in neuroscience research.” Progress in Neurobiology, 67(5), [2] Imaging Technology Group (2005). “Three-Dimensional Printing: Z406.” Beckman Institute for Advanced Science and Technology at the University of Illinois. Retrieved 1 March [3] Serway, R. & Jewett, J. (2004). Physics for Scientists and Engineers (6 th ed.). Belmont, CA: Thomson. [4] “Residential Hot Water Floor Heat Design and Installation Guide.” Infloor Heating Systems. Retrieved 28 February [5] Taylor, et al. (2007). “Study of two devices used to maintain normothermia in rats and mice during general anesthesia.” Journal of the American Association for Laboratory Animal Science. 46:5, pg [6] Sikoski et al. (2007). “Comparison of heating devices for maintaining body temperature in anesthetized laboratory rabbits (Oryctolagus cuniculus).” Journal of the American Association for Laboratory Animal Science. 46:3, pg: Small Animal Heating Pad-$51.00 HTP-1500 Circulator-$ Plastic Materials and Adhesive-$  Total-$ Ian Rowland, who performs regular imaging of rodents at the UW Hospital as part of his research, requested a stereotactic device that minimizes the movement of the rat while being imaged. The ideal design would also incorporate a heating device to warm the rat to prevent hypothermia and be able to provide the rat with the proper anesthesia. Our prototype is able to effectively restrain and align the animal for optimal imaging, delivers the necessary anesthetic, and includes a design for heating. Heating Pad – Uses circulating warm water to keep rat warm while anesthetized. HTP-1500 – Heats and circulates water to the heating pad with +/- 1 o F accuracy. Tooth Bar – Hooks around rat’s teeth, then slides back and fastens to secure rat. Ear Pegs – Keep rat’s head level and secure, adjustable for various size rats. Anesthetic Assembly – Slides along track and features removable mask for easier access to rat. Polycarbonate Cradle – Inserted into MRI coil, can adjust height for proper alignment. Tube to Anesthetic System