Evaluation of imaging performance of major image guidance systems
- Author:
Chan MF*
;
Yang J
;
Song Y
;
Burman C
;
Chan P
;
Li S
- Publication Type:Journal Article
- Keywords:
Cone beam CT, MVCT, tomotherapy, image quality, IGRT
- From:Biomedical Imaging and Intervention Journal
2011;7(2):1-7
- CountryMalaysia
- Language:English
-
Abstract:
Purpose: The imaging characteristics of two popular kV cone-beam CT (CBCT) and two MVCT systems utilised in
image-guided radiation therapy (IGRT) were evaluated.
Materials and methods: The study was performed on Varian Clinac iX, Elekta Synergy S, Siemens Oncor, and
Tomotherapy. A CT phantom (Catphan-504, Phantom Laboratory, Salem, NY) was scanned for measurements of image
quality including image noise, uniformity, density accuracy, spatial resolution, contrast linearity, and contrast resolution.
The measurement results were analysed using in-house image analysis software. Reproducibility, position correction,
and geometric accuracy were also evaluated with markers in a smaller alignment phantom. The performance evaluation
compared volumetric image properties from these four systems with those from a conventional diagnostic CT (CCT).
Results: It was shown that the linearity of the two kV CBCT was fairly consistent with CCT. The Elekta CBCT
with half-circle 27-cm FOV had higher CT numbers than the other three systems. The image noises of the Elekta kV
CBCT, Siemens MV CBCT, and Tomotherapy fan-beam CT (FBCT) are about 2-4 times higher than that of the Varian
CBCT. The spatial resolutions of two kV CBCTs and two MV CBCTs were 8-11 lp/cm and 3-5 lp/cm, respectively.
Conclusion: Elekta CBCT provided a faster image reconstruction and low dose per scan for half-circle scanning.
Varian CBCT had relatively lower image noise. Tomotherapy FBCT had the best uniformity.
- Full text:W020150914374305700318.pdf
