Accurate markerless respiratory tracking for gated whole body PET using the Microsoft Kinect

The motion due to respiration is responsible for greatly reducing image quality of whole body positron emission tomography, PET. A simple method to produce a respiratory signal to enable gating of PET listmode data using the Microsoft Kinect, a consumer grade 3D scanner, is presented. Phantom data produced by a sinusoidally oscillating phantom being tracked by an existing commercially available respiratory monitoring system and a Kinect based contactless tracking system shows that the Kinect system outperforms the Varian RPM tracking by producing higher resolution traces. When testing the Kinect using human subjects, the collected surface trace is sensitive enough to detect the patient´s heart rate. This has potential for improving motion correction of whole body imaging by including extra surface information provided by the Kinect, in addition to the basic respiratory signal.