Measurement of computed tomography dose profile with pitch variation using Gafchromic XR-QA2 and thermoluminescence dosimeter (TLD)

13th South-East Asian Congress of Medical Physics 2015

物理学;医药卫生

Purwaningsih, S.^1 ; Lubis, L.E.^1 ; Pawiro, S.A.^1 ; Soejoko, D.S.^1

Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, Indonesia^1

关键词: Adult head;    Axis rotation;    Dose profile;    Dose range;    GafChromic films;    Measurement positions;    Pattern curves;    Thermoluminescence dosimeter;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/694/1/012046/pdf
DOI  :  10.1088/1742-6596/694/1/012046

学科分类：卫生学

来源: IOP

【 摘 要 】

This research was aimed to check the patterns of dose profile on adult and pediatric head scan. We compared measurement result on dose profile along the z- axis rotation at peripheries and center phantom with a variety of pitch, i.e. 0.75, 1, 1.5 for adult and pediatric head protocol, keeping the rest of the scan parameters constant. Measurements were performed on homogeneous, cylindrical PMMA phantom with diameters of 16 and 10 cm using XR-QA2 Gafchromic film and TLD as dosimeters. The measurement result indicated a decrease in the dose about 50% and 47% for adult and pediatric head scan with the increase of pitch. For 0.75 value of pitch adult head scan, dose range for each position were (2.4 - 5.0) cGy, (3.1 - 5.3) cGy, (2.2 - 4.5) cGy, (2.8 - 5.3) cGy, and (3.3 - 5.6) cGy for position of center, 3, 6, 9 and 12 o'clock peripheral phantom position respectively. Dose profile for adult and pediatric head scan protocols has pattern curve with the maximum dose in the middle and tendency of symmetry near the edges, with different the plateau length along z- axis direction in accordance to the measurement position in the phantom.