Convolution-Based Truncation Correction for C-Arm CT Using Scattered Radiation
Patient dose reduction in C-arm computed tomography by volume-of-interest (VOI) imaging is becoming an interesting topic for many clinical applications. One limitation of VOI imaging that remains is the truncation artifact in the reconstructed 3-D volume. This artifact can either be a cupping effect towards the boundaries of the field-of-view (FOV) or an offset in the Hounsfield values of the reconstructed voxels. A new method for the correction of truncation artifacts in a collimated scan is introduced in this work. Scattered radiation still reaches the detector and is detected outside of the FOV, even if axial or lateral collimation is used. By reading out the complete detector area, we can use the scatter signal to estimate the truncated parts of the object: The scattered radiation outside the FOV is modeled as a convolution with a scatter kernel. This new approach is called scatter correction. The reconstruction results using Scatter convolution are at least as good or better than the results with a state-of-the-art method. Our results show that the use of scattered radiation outside the FOV improves image quality by 1.8 %.
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- Chintalapani G, Chinnadurai P, Maier A, et al. The value of volume of interest (VOI) C-arm CT imaging in the endovascular treatment of intracranial aneurysms: a feasibility study. Procs ASNR. 2012;12-O-1509-ASNR.Google Scholar
- Zeng L. Medical Image Reconstruction. 1st ed. Heidelberg: Springer Verlag; 2010.Google Scholar
- Kolditz D, Kyriakou Y, Kalender WA. Volume-of-interest (VOI) imaging in C-arm flat-detector CT for high image quality at reduced dose. Med Phys. 2010;37(6):2719–30.Google Scholar
- Kudo H, Courdurier M, Noo F, et al. Tiny a priori knowledge solves the interior problem in computed tomography. Phys Med Biol. 2008;53(9):2207–31.Google Scholar
- Hsieh J, Chao E, Thibault J, et al. A novel algorithm to extend the CT scan field-of-view. Med Phys. 2004;31(9):2385–91.Google Scholar
- Dennerlein F, Maier A. Region-of-interest reconstruction on medical c-arms with the ATRACT algorithm. Medical Imaging 2012: Physics of Medical Imaging. 2012;8313:83131B–83131B–9.Google Scholar
- Xia Y, Maier A, Dennerlein F, et al. Efficient 2D filtering for cone-beam VOI reconstruction. IEEE MIC. 2012;P. to appear.Google Scholar
- Chityala R, Hoffmann KR, Bednarek DR, et al. Region of interest (ROI) computed tomography. Proc Soc Photo Opt Instrum Eng. 2004;5745(1):534–41.Google Scholar
- Rührnschopf EP, Klingenbeck K. A general framework and review of scatter correction methods in x-ray cone-beam computerized tomography. Part 1+2. Med Phys. 2011;38(7):4296–311, 5186–99.Google Scholar
- Siewerdsen JH, Daly MJ, Bakhtiar B, et al. A simple direct method for x-ray scatter estimation and correction in digital radiography and cone-beam CT. Med Phys. 2006;33(1):187–97.Google Scholar