Awake Animal SPECT Project

The Jefferson Lab Detector and Imaging Group in collaboration with Oak Ridge National Laboratory (Dr. Justin Baba), Johns Hopkins University (Dr. Martin Pomper) and the University of Sydney (Dr. Steve Meikle) is developing an imaging methodology that utilizes SPECT and X-ray CT for small animal research. The primary challenging task of this project is to develop a SPECT imaging system to allow molecular imaging of unrestrained and un-anesthetized mice. Present methods of performing SPECT imaging with mice require the animals to be anesthetized or physically restrained during image acquisition. Both methods of restraint have the potential to interfere with the physiological and neurological processes being investigated. In the initial focus of the project, tracking of the orientation and location of the mouse's head during SPECT imaging is accomplished through a pair of CMOS optical cameras that image IR retro-reflectors attached to the mouse's head. The gamma-ray projection data is reconstructed into a fixed small animal reference frame based on the time-varying animal orientation data. The goal is to develop instrumentation to acquire high-resolution volumetric SPECT images of the head region of an unrestrained, un-anesthetized mouse and to register these image volumes with microCT data sets of the same mouse acquired before or after the SPECT scan. The animal will be anesthetized during the microCT scan. Jefferson Lab is coordinating the entire effort and is developing high spatial resolution gamma cameras 10 cm x 20 cm in size for the SPECT system. The system is installed in the animal research facility at Johns Hopkins University where it is being tested with awake mice.

References:
Weisenberger AG et al., IEEE Trans Nucl Sci. 2005; 52: 638-644
Weisenberger AG et al., Small-Animal SPECT Imaging. Eds. M. A. Kupinski, H. H. Barrett (New York: Springer, 2005), 239-243
Gleason SS et al., 2004 IEEE Nuclear Science Symposium Conference Record. J. Anthony Seibert, Ed. Rome, Italy, October 16-22, 2004. ISBN 0-7803-8701-5