Studies on the calibration of mammography automatic exposure mode with computed radiology

Objective To realize the optimization of image quality and radiation dose by correcting mammography automatic exposure,according to automatic exposure controlled mode of mammography film-screen system . Methods The film-screen system(28 kV) was applied to perform automatic exposure of plexiglass(40 mm) and get the standard dose of exposure, the exposure mode of CR base on LgM =2.0 was rectified, which was divided into 10 steps. Mammary glands pattern(Fluke NA18-220) were examined with CR( 26,28, and 30 kV ) by the automatic exposure mode corrected. The exposure values(mAs) were recorded. CR image was diagnosed and evaluated in double blind way by 4 radiologists according to American Collage of Radiology(ACR) standard. Results Based on the standard of CR automatic exposure with the dose higher than the traditional exposure of film-screen system, the calibration of mammography automatic exposure was accomplished. The test results of the calibrated mode was better than the scoring system of ACR. Conclusions Comparative study showed improvement in acquiring high-quality image and reduction of radiation dose. The corrected mammography automatic exposure mode might be a better method for clinical use. Key words: Computed radiology; Mammography; Image quality; Radiation dose