Optimization of image process parameters of digital radiography

Objective: To reduce the effective dose and maintain the image quality by adjusting the image processing parameters in the lumbar spine examinations. Methods: This study investigated the influence of image processing parameters on image quality of Philips DR system by evaluating image quality of CDRAD 2.0 phantom. The parameters include detail contrast enhancement, noise compensation, unsharp masking and unsharp masking kernel. The entrance surface dose of phantom was measured by Solidose meter. A synthetical parameters optimization project was proposed by analyzing the results of the investigation. This project was also testified by phantoms. Results: Important effects were the main effects of DCE, unsharp masking and kernel at the clinically used tube potential of 70 kVp (F=91.45, 373.79, 429.88, P<0.05). These effects indicated an increase of the IQF about 20 units with increasing unsharp masking, while an increase of DCE and kernel led to decrease of IQF about 10 and 21 units. When the tube potential was increased to 85 kV, keeping the settings of the process parameters unchanged, the IQF increased. The results showed statically significant difference (t=5.31, P<0.05). Conclusion: It is possible to lower the effective dose to the patient by the use of a higher tube potential and maintain a good image quality, and it will have little influence on clinic diagnosis through the most optimal setting of the process parameters. (authors)