The Influence of X-Ray Tube Current-Time Variations Toward Signal to Noise Ratio (SNR) in Digital Radiography: A Phantom Study

Abstract

Several image enhancement applications can be used to increase SNR and brightness. However, if the setting of tube current-time is too high, the application can not reduce the radiation dose. So, It is necessary to test tube current-time variations on the SNR value and image quality to determine the effect on body organs and radiation dose. This study aims to determine the influence of tube current-time on SNR and with this research is expected to be an input for radiographers in the field to pay attention to parameter settings for patients. We compared five tube current-time variations on the Antebrachii examination by using Phantom (58 kV, 32 mA, 50 mSec), (58 kV, 100 mA, 50 mSec), (58 kV, 32 mA, 5 mAs), (58 kV , 32 mA, 5 mAs) and (58kV, 100 mA, 5 mAs). Then we made a circle of ROI with a diameter of 0.2 cm2 on the Bone, Soft-tissue and Air sections in that four tube current-time variations, each of which has 7 ROI points tocalculate the SNR and the radiation dose is seen from the image. There is a difference in SNR on tube current-time changes and affects the image quality with an Adjusted R square value of 0.003 and 0.865. It shows that there is a change in tube current that affects the Signal to Noise Ratio between organs. Since it is proven that changes in tube current-time affect image quality, further research can formulate an ideal parameter for the examination of each organ.