Statement of Benefit to California:
Year 1The overall aim of this project is to develop a combined MRI and SPECT system for tracking stem cell migration in small animals. During the first year we were able to build a proto-type using a single detector and obtain images of physical objects to determine the minimum spatial resolution. Our studies indicate that the SPECT part of the system is able to image objects as small as 2mm in size. The resolution of the MRI component is much better and around 200 micrometers. We were able to make both of these systems work simultaneously to acquire simultaneous MRI and SPECT images. We also obtained preliminary images using a mouse model where one can see both the radio-isotope distribution via SPECT and high resolution anatomic information via MRI. The results have been published in two different journals.
Year 2The overall objective of this project was the design and construction of a combined MRI and SPECT system for tracking stem cell migration in small animals. During this reporting period, the system construction was finalized and several imaging tests were performed on both physical phantoms and mice. Integration and automated control of an MR-compatible motor was completed and utilized to rotate the system’s gantry to allow for tomographic imaging. The detection sensitivity of the system was evaluated using phantoms. The results demonstrate the system’s ability to detect and localize small amount of radioactivity, as would be required for stem cell tracking. Finally, small compartments of radioactivity were implanted at various locations within several mice and imaged using the MRSPECT system. The results demonstrate the feasibility of stem cell tracking in a live animal.