The Optimization Study Of Image Quality And Dose In CR Mammography

ObjectiveThis study aimed to investigate the difference of image quality between manual exposure and automatice exposure control (AEC) in a digital mammography, and the effect of image post-processing on improvement of image quality. To confirm the possibility of reducing patient dose through the methods of maunual exposure and image post-processing in digital mammography.MethodCDMAM 3.4 phantom and TORMAM phantom were selected and exposured in a CR system in 5 different phantom thickness. Under each thickness there are 4 dose levels. These corresponded to 100%,80%,60% and 40% dose. Three observers interpreted the all image. Each image was scored twice:unprocessed images and post-processed image. The differences of image quality were compared between three lower dose images and 100% dose image.ResultsThe image quality can be improved through image post-processing. The patient dose could be reduced from 20% to 40% through image poss-processing when the equivalent breast thickness is 30 and 35mm. When the equivalent breast thickness up to 40,45, and 50mm, the dose can be reduced from 40% to 60%. For filament details, the dose can be reduced 20% after image post-processing.For the circular details, the effects of image post-processing appear to significant and the dose can be reduced by 60%. However for the partical details, the effect of image post-processing on image quality is not obvious.ConclusionsThe image quality can be improved through image post-processing. For different equivalent breast thickness, the patient dose can be reduced from 20% to 60% through manual exposure and image post-processing. The effects of image post-processing are different on different phantom details.For filament details and circular details, the improvement of image quality is significant.The dose can be decreased by within 20% and 60% separately. However for the partical details, the effect of image post-processing on image quality is not obvious.