Résumé
Objective To test the overall characteristic curve on a computed radiography system. Methods Imaging plate was exposed by scale-time expose using conventional X-ray equipment. It was processed by CR system. Density of different optical density wedge on CR film was measured by using densimeter. Then, characteristic curve was plotted. Results (1) Overall characteristic curve of CR system was affected by gradation processing. (2) Average gradient of overall characteristic curve was 1.98, 3.10, and 3.75 when GA was 0.8,1.4, and 2.4. (3) Overall characteristic curve rotated around rotation center when rotation amount was changed. Conclusion According to the diagnostic purpose and different body position, rotation amount can be selected, and different contrast imaging can be acquired.