Analysis of the Effect of Phantom CT Scan Diameter Variations on Radiation Dose with IndoseCT

Abstract

The dose received by a patient who performs a CT scan is influenced by several factors, namely slice thickness, pitch, position and size of the patient, range of scanning and type of scanning. The amount of radiation dose received from the scan also depends on phantom geometry, form and material. The method of calculating a patient's dose on a CT scan is known as the Computed Tomography Dose Index (CTDI). According to research that has already been carried out, it is explained that CTDI represents only the surface dose of the body. SSDE is then used to calculate the central dose of phantom and phantom edge. The purpose of this study was to determine the dosage size for variations in phantom diameter and SSDE values with the IndoseCT program for variations in phantom diameter. The measurement method in this study was carried out using a piranha detector and IndoseCT software. The results of the study found that there were differences in the values of CTDIc, CTDIw, and CTDIvol, each having a range of 0.93% to 147.96%, 26.65% to 62.48%, 11.51% to 41.46%. SSDE values for phantom size 8 cm, 16 cm, 24 cm, 32 cm and 40 cm respectively are as follows: 29 mGy, 23.09 mGy, 16.86 mGy, 12.35 mGy, 9.27 mGy. The conclusion of this study is that the greater the effective diameter of phantom the smaller the SSDE.