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The adaptation and investigation of cone-beam CT reconstruction algorithms for horizontal rotation fixed-gantry scans of rabbits
- Source :
- Physics in Medicine & Biology
- Publication Year :
- 2021
- Publisher :
- IOP Publishing, 2021.
-
Abstract
- Fixed-gantry radiation therapy has been proposed as a low-cost alternative to the conventional rotating-gantry radiation therapy, that may help meet the rising global treatment demand. Fixed-gantry systems require gravitational motion compensated reconstruction algorithms to produce cone-beam CT (CBCT) images of sufficient quality for image guidance. The aim of this work was to adapt and investigate five CBCT reconstruction algorithms for fixed-gantry CBCT images. The five algorithms investigated were Feldkamp–Davis–Kress (FDK), prior image constrained compressed sensing (PICCS), gravitational motion compensated FDK (GMCFDK), motion compensated PICCS (MCPICCS) (a novel CBCT reconstruction algorithm) and simultaneous motion estimation and iterative reconstruction (SMEIR). Fixed-gantry and rotating-gantry CBCT scans were acquired of 3 rabbits, with the rotating-gantry scans used as a reference. Projections were sorted into rotation bins, based on the angle of rotation of the rabbit during image acquisition. The algorithms were compared using the structural similarity index measure root mean square error, and reconstruction time. Evaluation of the reconstructed volumes showed that, when compared with the reference rotating-gantry volume, the conventional FDK algorithm did not accurately reconstruct fixed-gantry CBCT scans. Whilst the PICCS reconstruction algorithm reduced some motion artefacts, the motion estimation reconstruction methods (GMCFDK, MCPICCS and SMEIR) were able to greatly reduce the effect of motion artefacts on the reconstructed volumes. This finding was verified quantitatively, with GMCFDK, MCPICCS and SMEIR reconstructions having RMSE 17%–19% lower and SSIM 1% higher than a conventional FDK. However, all motion compensated fixed-gantry CBCT reconstructions had a 56%–61% higher RMSE and 1.5% lower SSIM than FDK reconstructions of conventional rotating-gantry CBCT scans. The results show that motion compensation is required to reduce motion artefacts for fixed-gantry CBCT reconstructions. This paper further demonstrates the feasibility of fixed-gantry CBCT scans, and the ability of CBCT reconstruction algorithms to compensate for motion due to horizontal rotation.
- Subjects :
- Rotation
Mean squared error
Computer science
0299 Other Physical Sciences
Iterative reconstruction
030218 nuclear medicine & medical imaging
03 medical and health sciences
patient rotation
0302 clinical medicine
Motion estimation
Image Processing, Computer-Assisted
Animals
Radiology, Nuclear Medicine and imaging
Four-Dimensional Computed Tomography
Angle of rotation
Motion compensation
Radiological and Ultrasound Technology
Phantoms, Imaging
Reconstruction algorithm
Cone-Beam Computed Tomography
image reconstruction
Compressed sensing
030220 oncology & carcinogenesis
Rabbits
Artifacts
Algorithm
Rotation (mathematics)
Algorithms
Subjects
Details
- ISSN :
- 13616560 and 00319155
- Volume :
- 66
- Database :
- OpenAIRE
- Journal :
- Physics in Medicine & Biology
- Accession number :
- edsair.doi.dedup.....5e4b798405ed6ff1dffac0822b34464c
- Full Text :
- https://doi.org/10.1088/1361-6560/abf9dd