Non-invasive motion tracking for awake rat brain positron emission tomography with in vivo validation.

Small animal positron emission tomography (PET) imaging is an indispensible tool for basic research, drug discovery and development. However, in contrast to clinical scanning, animals need to be immobilized during the scan using anesthetics. Unfortunately, in neuroscience experiments, these anesthetics can alter and obscure the outcome of the PET study. Therefore, we are developing techniques to enable PET scanning of awake and unrestrained rats. The technique will measure the position and motion of the rat's head during the PET scan so that a PET image can be formed as if the rat did not move. We will develop minimally and non-invasive techniques to measure this motion. One method is based on miniscule radioactive point sources that are pasted on the animal's head; the other makes use of a 3D optical camera. These novelties will boost the practicality and relevance of awake rat brain PET. Compared to the current invasive method that uses a large checkerboard marker these methods have many advantages: it does not introduce animal stress, is less prone to errors due to skin motion and can be used in scanners with small scanner bores. A full- scale small animal experiment visualizing the brain response to amphetamine will demonstrate the practicality of the method and show the impact of awake versus anesthetized scanning. The new tracking techniques and the in vivo validation will finally establish awake and unrestrained small animal PET imaging as a valid imaging protocol.

Keywords:PET SCAN

Disciplines:Biochemistry and metabolism, Medical biochemistry and metabolism