Lubis Lukmanda Evan, Najmah Windi Dliya, Muliyanti Yuni, Hariyati Ika, Ryangga Dea, Mart Terry, Bosmans Hilde, Soejoko Djarwani Soeharso
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Indonesia.
Center for Medical Physics and Biophysics, Faculty of Mathematics and Natural Sciences, Institute for Applied Sciences, Universitas Indonesia, Indonesia.
J Med Phys. 2023 Oct-Dec;48(4):402-408. doi: 10.4103/jmp.jmp_92_23. Epub 2023 Dec 5.
This article aims to present the development, construction, and evaluation of an alternative computed tomography dose index (CTDI) phantom. Epoxy resin was mixed with an iodine-based contrast agent to produce radiological characteristics resembling polymethyl methacrylate (PMMA) as a standard CTDI phantom. As a preliminary study, testing was carried out using computed tomography images (80 and 120 kVp) on 12 variations of epoxy-iodine resin mixtures to obtain relative electron density () values and effective atomic numbers () of the samples. The alternative CTDI phantoms were then constructed with a resin-iodine mixture using iodine concentrations that yield on closest and values to those of PMMA. The evaluation was carried out by comparing dose measurement results at various energies between the alternative phantom and the International Electrotechnical Commission-standard CTDI phantom. At a concentration of 0.46%, the epoxy resin has and with a deviation against PMMA of 0.12% and 1.58%, respectively, so that composition was chosen for the alternative CTDI phantom construction. The average dose discrepancy values were 5% and 1%, respectively, for the head and body phantoms in the tested tube voltages of 80 kVp, 100 kVp, 120 kVp, and 135 kVp. The Student's -test result between the alternative and the standard phantoms also showed < 0.05, indicating the comparability of the alternative CTDI phantom with the standard CTDI phantom.
本文旨在介绍一种替代型计算机断层扫描剂量指数（CTDI）体模的开发、构建和评估。将环氧树脂与碘基造影剂混合，以产生类似于作为标准CTDI体模的聚甲基丙烯酸甲酯（PMMA）的放射学特征。作为一项初步研究，使用计算机断层扫描图像（80和120 kVp）对12种环氧树脂-碘树脂混合物变体进行测试，以获得样品的相对电子密度（）值和有效原子序数（）。然后使用碘浓度构建替代CTDI体模，该碘浓度产生的和值与PMMA的最接近。通过比较替代体模和国际电工委员会标准CTDI体模在各种能量下的剂量测量结果进行评估。在浓度为0.46%时，环氧树脂的和与PMMA的偏差分别为0.12%和1.58%，因此选择该成分用于替代CTDI体模的构建。在80 kVp、100 kVp、120 kVp和135 kVp的测试管电压下，头部和体部体模的平均剂量差异值分别为5%和1%。替代体模和标准体模之间的学生t检验结果也显示<0.05，表明替代CTDI体模与标准CTDI体模具有可比性。
