Assessing a system to detect patient motion in SPECT imaging using stereo optical cameras

Patient motion, which causes artifacts in reconstructed images, can be a serious problem in SPECT imaging. If patient motion can be detected and quantified, the reconstruction algorithm can compensate for the motion. Most previous approaches to detecting patient motion have relied on only the acquired projection data, using, for example, consistency checks or motion-tracking to detect motion. Our approach is based on optical tracking of the patient using a pair of web cameras to acquire stereo images. The stereo images are analyzed by a visual tracking system (VTS) that detects changes in the stereo images over time to track locations on the patient surface. Patient surface motion can then be used to infer motion within the patient body, which will be used to correct for patient motion. The system consists of a three-headed SPECT system and two web cameras connected to a PC.