Effect of Different Sensitivity on Image Quality of Digital Chest Radiography / 中国医学影像学杂志

ABSTRACT

Purpose To investigate the effect of sensitivity on image quality and radiation dosage of digital chest radiography. Materials and Methods A total of 300 healthy people undergoing chest X-ray examination were randomly enrolled and divided into two groups according to body weight (150 people with normal weight and 150 overweight), which were further randomly divided into three subgroups (S200 subgroup with low-sensitivity, S400 subgroup with mid-sensitivity, S800 subgroup with high sensitivity, each subgroup contained 50 people). With other parameters unchanged, digital chest photography with different sensitivities was performed to each subgroup (S200, S400 and S800, respectively), and then uploaded the data to PACS and recorded mAs value and dose area product (DAP) value for each time. Then the image quality was assessed by three doctors in terms of mAs value, DAP, image quality score and noise score. Results In all subgroups of normal weight, differences on mAs and DAP were significant (F=1443.191-1829.895, P0.05). In all overweight subgroups, differences in mAs, DAP, image quality score and noise score were significant (F=163.358-290.656, PS400>S800 (F=0.626-3.210, PS400>S800 (F=0.416-1.416, P0.05). In overweight group, there was no difference between subgroups of S200 and S400 (F=0.120-0.145, P>0.05); whilst differences between subgroups of S200 and S800 were significant, the same appeared in subgroups of S400 and S800 (F=1.655-2.360, P<0.05). Conclusion Radiation dose can be effectively controlled by regulating sensitivity with image quality unaffected. It is advisable to choose high-sensitivity photography for patients with normal weight and low or mid-sensitivity photography for overweight patients.