Keywords:
Performed at one institution, Experimental, Retrospective, Image registration, Computer Applications-General, CT, Lung
Authors:
S. Maehira1, T. Hiroki1, Y. Fujita2, K. Usui2, E. Kunieda1; 1Kanagawa/JP, 2Tokyo/JP
DOI:
10.26044/ecr2020/C-07928
Purpose
Accurate estimation for the effects of respiratory motion can potentially lead to more accurate diagnosis and treatment. In radiation therapy, for example, the motion is assessed for determination of planning margins1) and delivered dose assessment2). Although the respiratory motion has been modeled in a variety of ways for different purposes, the effects of different breathing maneuvers are not well known.
Respiration is generally divided into abdominal breathing and thoracic breathing. (Fig. 1, Fig. 2 ) The muscles used in abdominal breathing are the diaphragm for inspiration. The thoracic breathing is a respiration method that mainly involves movement of the ribs, where inspiration involves the external intercostal muscles. Previous studies have reported that lung motion depends not only on vital capacity but also on differences in these breathing maneuvers. Plathow et al. showed that different breathing maneuvers led to different levels of chest wall expansion with the same spirometric vital capacity3). However, these lung motion data have been collected from measurements of a limited number of points within the organ, the centroid, or the edge of the organ4). Moreover, these data do not consider organ deformation.
Deformable image registration (DIR) is prosses for deforming source image data sets into a target image sets. This study sought to characterize lung motion and deformation of different breathing maneuvers using DIR. This study is the first to quantitatively evaluate lung motion and deformation caused by the difference between abdominal breathing and thoracic breathing, which are typical breathing maneuvers, using DIR.