A method for sensitivity analysis of deviation factor for geometric correction of cone-beam CT system.
10.12122/j.issn.1673-4254.2023.07.20
- Author:
Hailong WANG
1
;
Guoqin LIN
1
;
Xiaoman DUAN
2
;
Mengke QI
1
;
Wangjiang WU
1
;
Janhui MA
3
;
Yuan XU
1
Author Information
1. School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China.
2. University of Saskatchewan, Saskatoon Saskatchewan, Canada.
3. Department of Radiotherapy, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
- Publication Type:Journal Article
- Keywords:
cone beam CT;
geometric correction;
image reconstruction;
steel ball point accuracy deviation
- MeSH:
Algorithms;
Calibration;
Cone-Beam Computed Tomography;
Steel
- From:
Journal of Southern Medical University
2023;43(7):1233-1240
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To propose a sensitivity test method for geometric correction position deviation of cone-beam CT systems.
METHODS:We proposed the definition of center deviation and its derivation. We analyzed the influence of the variation of the three-dimensional spatial center of the steel ball point, the projection center and the size of the steel ball point on the deviation of geometric parameters and the reconstructed image results by calculating the geometric correction parameters based on the Noo analytical method using the FDK reconstruction algorithm for image reconstruction.
RESULTS:The radius of the steel ball point was within 3 mm. The deviation of the center of the calibration parameter was within the order of magnitude and negligible. A 10% Gaussian perturbation of a single pixel in the 3D spatial coordinates of the steel ball point produced a deviation of about 3 pixel sizes, while the same Gaussian perturbation of the 2D projection coordinates of the steel ball point produced a deviation of about 2 pixel sizes.
CONCLUSION:The geometric correction is more sensitive to the deviation generated by the three-dimensional spatial coordinates of the steel ball point with limited sensitivity to the deviation generated by the two-dimensional projection coordinates of the steel ball point. The deviation sensitivity of a small diameter steel ball point can be ignored.
