Characterization of a cone beam optical scanner

7th International Conference on 3D Radiation Dosimetry

Ravindran, P.B.^1 ; Thomas, H.M.^2

Department of Radiation Oncology, Christian Medical College, Vellore, India^1

Photonics Division, School of Advanced Sciences, Vellore Institute of Technology, Vellore, India^2

关键词: Contrast to noise ratio;    Dose distributions;    Geometrical accuracy;    Optical scanners;    Performance characteristics;    Radiotherapy applications;    Reconstructed image;    Spiral geometries;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012064/pdf
DOI  :  10.1088/1742-6596/444/1/012064

来源: IOP

【 摘 要 】

The use of radiochromic FX gel for mapping 3D dose distribution is hampered by the diffusion of gel and the slow scanning techniques. The development of fast optical cone beam scanning has improved the chances of using radiochromic gel as a feasible dosimeter for radiotherapy applications. In this work an optical cone beam scanner has been developed in-house and its performance characteristics have been studied. The reconstructed image of the optical scanner was analyzed by studying the resolution, signal-to-noise ratio and contrast to noise ratio (CNR). The resolution of the optical cone beam CT scanner was studied by scanning a catheter of 1 mm outer diameter and the scanner was able to detect the catheter. The geometrical accuracy of the reconstruction was studied by placing catheters in spiral geometry in the gel phantom and measuring the distances. It has been observed that the in-house Optical Cone beam scanner is suitable for scanning radiochromic gels for radiotherapy applications.