Sparse-view statistical image reconstruction with improved total variation regularization for X-ray micro-CT imaging
| Autor: | Mohammad Reza Fouladi, Arman Rahmim, Hossein Ghadiri, Mohammad Reza Ay, Golshan Mahmoudi |
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| Rok vydání: | 2019 |
| Předmět: |
Mean squared error
010308 nuclear & particles physics Image quality Computer science Iterative reconstruction Total variation denoising computer.software_genre 01 natural sciences Imaging phantom 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Voxel 0103 physical sciences Piecewise Noise (video) Instrumentation Algorithm computer Mathematical Physics |
| Zdroj: | Journal of Instrumentation. 14:P08023-P08023 |
| ISSN: | 1748-0221 |
| Popis: | Sparse-view x-ray micro computed tomography (micro-CT) reconstruction algorithms via total variation (TV) optimize the data without introducing notable noise and artifacts, resulting in significant scanning time reduction while maintaining image quality. However, due to the piecewise constant assumption for the image, a conventional TV minimization often suffers from patchy artifacts in reconstructed images. Moreover, for lack of directional gradient in TV some directional information are lost. To obviate these drawbacks, in this study we develop a penalized weighted least-square (PWLS) strategy for micro-CT sparse-view image reconstruction by incorporating an adaptive weighted total variation in combination with an adaptive weighted diagonal total variation (AwTV+AwDTV) penalty term. The AwTV considers the vertical and horizontal gradients while the AwDTV uses the diagonal gradients. The associated weights which are defined based on the anisotropic edge properties of an image, are expressed as an exponential function and can be adaptively adjusted by the amount of the difference between voxel intensities to preserve the edge details. To evaluate the presented (AwTV+AwDTV)-PWLS algorithm, both qualitative and quantitative studies were performed by computer simulations and micro-CT data experiments. The Shepp-Logan phantom for computer simulation and the micro-CT water phantom and a rat skull for micro-CT experiments are employed to perform image reconstruction. To evaluate the performance of AwTV+AwDTV algorithm, we compared it with TV and AwTV reconstruction algorithms. The simulation results show that the presented (AwTV+AwDTV)-PWLS algorithm can achieve the lowest RMSE and highest PSNR, SSIM and MTF for different number of projections as compared to the AwTV and conventional TV algorithms. The micro-CT data results confirmed the superiority of the proposed (AwTV+AwDTV) method to the AwTV and TV methods for different number of projections. |
| Databáze: | OpenAIRE |
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