Evaluation of astructured-light 3D-scanner for respiratory gating in PET/CT in a clinical setting

Abstract: In this study a structured light prototype device was evaluated for the possible use as a respiratory gating device in PET/CT. The device functions by measuring the movement in the vertical direction of the obtained 3D-surface of the chest and abdomen with the breathing.The aim of the thesis was to evaluate if and in what way a respiratory signal could be measured for patients undergoing a PET/CT examination. The system was verified against a second gating device, Sentinel by C-RAD, for 15 healthy test-persons. A high Pearson correlation coefficient between the two systems was measured indicating a similar performance in the measurement of the respiratory phase, while there were some differences in the measurement of the mean peak-to-peak amplitude between the systems. 42 patients were examined with the device at Akademiska Sjukhuset in order to test if it were possible to measure a respiration signal from the patients in the PET/CT. An useful respiratory signal was obtained for 41 patients. The size of the FOV is large enough to cover two bed-positions in the PET/CT to be respiratory gated. The prototype device has the potential to be used as a respiratory gating device with the possible benefits of having a fully contact-less system. However, improvements of the 3D-surface quality has to be made in order to ensure a constant position of the respiratory gating point, as well as further testing about the ability to measure the amplitude accurate.