Effectiveness of Using AEC (Smart mA) System for Optimization of Dose and Image Quality on Abdominal CT Protocol

Abstract

This study aims to analyze Automatic Exposure Control (AEC) with Smart mA software on water phantom image quality and CTDIvol dose. The researched image quality is CT Number and noise. In addition, the CT Number is evaluated for accuracy, uniformity, and noise using the Noise Power Spectrum method. The results of image measurements with and without Smart mA on CT Number accuracy are still in the Standard range of ± 4 CT, the uniformity value of CT Number and noise is also still within the Standard, namely ± 2 CT. The use of Smart mA increases the noise value by 14.29%. The noise value from the noise power spectrum analysis when using Smart mA is higher than without using Smart mA. Meanwhile, the CTDIvol radiation dose from using Smart mA decreases by 52.33%. Image quality using Smart mA has a CT Number value almost the same or uniform with the test object, namely water phantom, so that the use of Smart mA can characterize body tissues well, but the noise value generated is more significant than without using Smart mA. Although the noise value generated by Smart mA is more excellent, visually, the noise value does not disturb the radiologist too much in determining the diagnosis because the image quality is still in good condition so that it can give a dose according to the patient's body thickness according to the ALARA principle. Keywords: CT Number, CTDIvol, AEC, NPS.