Effect of respiratory movement on cone beam computed tomography images.
- Author:
Chang GUO
;
Renming ZHONG
;
Guangjun LI
;
Chuanxian JI
;
Chengqiang LI
;
Hong QUAN
;
Sen BAI
- Publication Type:Journal Article
- MeSH:
Cone-Beam Computed Tomography;
Humans;
Lung Neoplasms;
diagnostic imaging;
Movement;
Phantoms, Imaging;
Respiration
- From:
Journal of Biomedical Engineering
2014;31(2):314-318
- CountryChina
- Language:Chinese
-
Abstract:
To investigate the impact of respiratory movement to determine the target volume on cone beam CT (CBCT) for lung tumor, we used CIRS dynamic thorax phantom (Model-CIRS008) to simulate the sinusoidal motion of lung tumor. With a constant amplitude, the ratio of the time of near-end-expiratory and near-end-inspiratory (E/I) changed when it was scanned with CBCT. We analyzed the contrast changes of target by extracting the CT value of each pixel on the center line of the target movement direction. The targets were contoured with region growing method and compared with the motion volume generated by the tumor trajectory method. The result showed that the contrast of near-end-expiratory increased and the contrast of near-end-inspiratory decreased with increasing E/I. The contoured volume generated by region growing method decreased with increasing E/I. When E/I = 4, the amplitude A = 1 cm, diameter of 1 cm and 3 cm target volumes were reduced by 48.2% and 22.7%. The study showed that CBCT was not suitable to be used to accurately determine the range of lung tumor movement. The internal target volume (ITV) may be underestimated in CBCT images.
