Effects of kV on Image Quality and Radiation Dose for Digital Radiography

Objective To study the correlation of kV with image quality and radiation dose for digital radiology(DR).Methods Quality assurance(QA) was performed with BARRACUDA system to make sure DR x-ray machine was in good condition.On condition that CDRAD 2.0 phantom was used,radiation dose and image quality parameters were recorded while changing kV.Results Image quality(IQ) was decreased with increasing tube voltage.IQ reached best at tube voltage of 70 kV and 90 kV with IQFinv 6.27 and 6.10,while least at 110 kV with IQFinv 4.27.Value of pixels were decreased by 13% when tube voltage was increased from 60 kV to 80 kV,but only changed by 2% when tube voltage was increased from 80 kV to 130 kV.Pattern noise was increased with tube voltage.Compared with that of 60 kV,pattern noise was respectively increased by 9.6% and 16.9% at 90 kV and 120 kV.Significant positive correlation was observed between IQFinv and DAP(P 0.05).Conclusion High image quality and effective control of radiation dose in examinees can obtain proper tube voltage and mAs in DR.