Respiratory signal extraction for 4D CT imaging of the thorax from cone-beam CT projections
Résumé
The purpose of this study was the four-dimensional (4D) imaging of a free-breathing thorax with the Elekta Synergy cone-beam (CB) for 4D radiotherapy. The first step consisted in facing the slowness of the acquisition by retrospectively sorting CB projections with a respiratory signal. We propose to extract the respiratory signal directly from thorax CBCT projections instead of using an external device (spirometer, infrared camera). We firstly simulated a set of CBCT images with a 4D CT model for the development and the validation of the method. From the simulation output, we secondly extracted, selected and integrated motion information to obtain the respiratory signal.