The determination of setting on X-ray equipment to get high image quality with low dosage in chest radiography using CNR ratio values

The purpose of this assessment is to determine the best optimum setting for getting the highest image quality with lowest dose radiation received by the chest phantom using general radiography system and computed radiography (CR) system. In the study nano dot were used to measure the radiation dose on the phantom at a certain location with variation of exposure parameters. The study involved two procedures which are varies kVp with fix mA, exposure time and others parameter for procedure 1. Then followed with second procedure by varies of mA and fix others parameter after getting the best setting of kVp to get highest image quality in procedure 1. The images quality parameter in term of contrast noise ratio (CNR) and dose in sievert unit were evaluated in the study. All the results at those setting parameters were analyzed. Based on the results the best optimum setting is at 100 kVp, 200 mA and 0.1 s with dose 0.760 mSv and CNR 7.94. This is only valid for the settings selected in the study. (author)