Detecting Patient Motion in SPECT Imaging Using Stereo Optical Cameras

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1. Introduction
Patient motion causes many problems in SPECT imaging, such as blur and other motion artifacts. If patient motion is excessive, it may be necessary to repeat an acquisition, with consequent cost and inconvenience. Previous approaches to motion detection relied on inconsistency checks or motion tracking, or were limited to rigid body parts, such as the head. The goal of this work is to design a more general system architecture for detecting, modeling, and correcting patient motion in SPECT imaging using information in addition to the emission counts themselves.


2. Procedure
Web cameras were mounted outside a 3-headed IRIX SPECT system to acquire optical images simultaneously with the gamma emission images
Before patient data can be acquired, the optical cameras must be calibrated to the gamma camera. The calibration and operation phases are sketched in Figure 2. Figures 3–5 show the processing steps during the operation phase.


3. Project Status
Calibration and Image Acquisition modules are complete. The Stereo Computation module is currently under development. Motion Detection, Interpolation, and Tomographic Reconstruction modules have not yet been implemented.