Motion Correction of Respiratory-Gated PET/CT Images Using Polynomial Warping

A respiratory motion during whole-body imaging has been recognized as a source of image quality degradation and reduces the quantitative accuracy of positron emission tomography (PET) study. The aim of this study is to correct respiratory gated PET/CT image using region growing and nonlinear warping. We utilized a commercially available optical laser sensor to detect respiratory motion during PET/CT scanning. The acquired data within the time bins corresponded to different positions within the breathing cycle and stored for the post motion correction. Motion data of diaphragm and chest wall were calculated by gated-CT image acquisition during the normal inspiration and expiration. This technique improves the quantitative specific activity of the tracer which is distorted because of the respiratory motion.