Small Animal Imaging

Imaging small animals used in drug testing requires exceptionally high spatial resolution to resolve tiny structures and accurately identify and size tumors and other lesions. In order to minimize the stress placed on animals during imaging, the sensitivity of the detector must be as high as possible, so as to minimize scan time. High detector sensitivity also allows the same animal to be used throughout a longitudinal study, by reducing the radiation dose that must be administered to a subject. In many cases computed tomography and volumetric imaging of test subjects is required, with both transmission (X-ray) and emission (injected radionuclide) imaging performed in order to obtain combined anatomical and functional imaging.

Low dose micro-CT (computed tomography) of a mouse. Both projection data and a CT reconstruction are shown.

In collaboration with RMD, the University of Arizona has developed a high resolution small animal SPECT device, FastSPECT III Molecular Imaging System. This device is capable of very high resolution radionuclide mouse imaging.

(Left) Picture of the FastSPECT III Molecular Imaging System developed by University of Arizona, in collaboration with RMD. It consists of a number RMD’s CsI:Tl scintillators read out by image intensified CCD sensors. (Middle) (a) The older lens coupled cameras and (b) the newer fiberoptic coupled system (Right) Picture of the multipinhole collimator used by the system.


Dynamic imaging using 99mTc MAG3 (~3.0mCi) with the FastSPECT III. Time-activity curves are shown for the mouse kidneys and bladder over the course of 30 minutes (1-second temporal resolution).

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Small Animal Imaging