An Approach for Automation of CT Number Linearity Measurement on the TOS Phantom Image
DOI:
https://doi.org/10.32628/IJSRST52411124Keywords:
CT number, CT number linearity, Noise.Abstract
Assessment of the computed tomography (CT) number linearity is an important part in the Quality Control (QC) procedures of CT images. An automated method is needed for simplify the measurement process of this parameter. This study aims to develop an automated method for measuring CT number linearity on the TOS phantom images scanned with Toshiba Aquilion Lightning CT scanner with variations of tube current, tube voltage, and slice thickness. The automation began with segmenting the phantom object with a threshold of - 200 Hounsfield units (HU). Then, the centroid was determined for the phantom mask. The air object inside the phantom and its centroid were segmented utilizing a threshold of - 900 HU. By performing a simple rotation operation between the two obtained centroids (i.e., phantom and air centroids), the central coordinates of Delrin, acrylic, nylon, and polypropylene materials were determined. CT number linearity and its coefficient of determination (R2) were calculated. The proposed method was evaluated with datasets scanned from variations of tube current, tube voltage, and slice thickness. The automated CT number linearity measurements were successfully developed. The CT number linearity showed acceptable results for all variations (R2>0.99). Moreover, no significant changes in CT numbers of all materials compared to the standard values were noticed.
References
- IAEA. Human Health Series No. 19. Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications. Vienna: IAEA. 2012.
- Genisa M, Shuib S, Rajion ZA, Arief EM, Hermana M. Density estimation based on the Hounsfield unit value of cone beam computed tomography imaging of the jawbone system. Proceedings of the Institution of Mechanical Engineers. 2018;232(12):1168-1175
- Lubis LE, Hariyati I, Ryangga D, Mu’minah IAS, Mart T, Soejoko DS. Construction and evaluation of a multipurpose performance check phantom for computed tomography. Atom Indonesia. 2020; 46(2):69-75.
- CIRS Inc. AAPM CT Performance Phantom Datasheet. 2013.
- Gammex Inc. Automated CT Software (ACTS). User’s Guide. 2008.
- The Phantom Laboratory. Catphan 500 and 600 Product Guide. 2021.
- Suyudi I, Anam C, Sutanto H, Triadyaksa P, Fujibuchi T. Comparisons of Hounsfield Unit Linearity between Images Reconstructed using an Adaptive Iterative Dose Reduction (AIDR) and a Filter Back-Projection (FBP) Techniques. Journal of Biomedical Physics and Engineering. 2020;10(2): 215-224.
- Anam C, Amilia R, Naufal A, Budi WS, Maya AT, Dougherty G. The automated measurement of CT number linearity using an ACR accreditation phantom. Biomedical Physics & Engineering Express. 2023;9: 017002.
- Noviliawati R, Anam C, Sutanto H, Dougherty G, Mak’ruf MR, Automatic validation of the gantry tilt in a computed tomography scanner using a head polymethyl methacrylate phantom. Polish Journal of Medical Physics and Engineering. 2021;27(1):57-62.
- Anam C, Naufal A, Budi WS, Sutanto H, Haryanto F, Dougherty G. IndoQCT: A platform for automated CT image quality assessment. Med Phys International. 2023;11(2):328-336.
- BAPETEN, Peraturan Badan Pengawas Tenaga Nuklir No. 2 Tahun 2018. Uji Kesesuaian Pesawat Sinar-X Radiologi Diagnostik dan Intervensional. Jakarta. 2018; 46-47.
- Chand B, Priyamvda, Kumar M, Prasher S, Kumar M. Effect of CT number to relative electron density curves acquired at different tube voltage and current on radiotherapy dose calculation. Journal of Physics: Conference Series. 2022;2267:012140.
Downloads
Published
Issue
Section
License
Copyright (c) IJSRST
This work is licensed under a Creative Commons Attribution 4.0 International License.