Research on the Relationship between Breathing and Lung Organ's Motion Based on Fluoroscopic Imaging

It is an important problem in dynamic radiotherapy for lung cancer, which has not been solved, to detect the lung tumor's motion indirectly.The key of this problem is to create a relationship model between the patient's breathing or the motion of thorax and abdomen with the lung organ's motion.Considering this problem, the patient's respiratory signal and fluoroscopic images of the lung are adopted as research object to study the relationship between the patient's breathing and the lung organ's motion caused by breathing.The patient's respiratory signal was acquired by a respiratory detecting device based on pressure detecting, and the optical flow method was adopted to track the motion of the diaphragm in the fluoroscopic image sequence, and the waveforms of the diaphragm's motion and the respiratory signal were compared.Experimental results show that there is a phase discrepancy between the patient's breathing and the lung organ's motion caused by breathing.After phase aligning, a linear relationship can be found between breathing and the lung organ's motion.