A practical rebinning-based method for patient motion compensation in SPECT imaging

Single photon emission computed tomography (SPECT) studies require the patient to remain motionless for protracted period of time. But considerable patient discomfort can lead to patient motion, which will introduce the image artifacts and degrade resolution. If the patient motion can be detected, it is possible to compensate for the motion to reduce or eliminate the artifacts. In this paper a method based on visual-tracking-system (VTS) is presented to compensate for the patient motion during data acquisition. VTS will get the exact position and orientation that are independent of the SPECT system. During data acquisition each detected photon produces an event that is written to a file. Each event includes the photon location, energy and time. The list of events is adjusted by compensation algorithm to produce a corrected set of motion-free observations. In the compensation process, the projections can be repositioned and reconstructed with ordered subsets expectation maximization (OSEM) algorithm. By comparing the corrected result and uncorrected result our compensation method can be assessed.