A method to modify mammography images to a appear as if acquired using different radiographic factors

摘要

This work presents and tests a new method of adapting mammography images to appear as if acquired using different radiographic factors by changing the signal and noise within the images. A Hologic Selenia Dimensions was used for the validation of the conversion method. Two set of images were acquired for the validation, one set was of 30, 45 and 60 mm thick polymethyl methacrylate (PMMA) acquired for a range of beam qualities while the other set was the same except for the addition of a contrast object of 2 and 4 mm thick pieces of PMMA. One set of images was then adapted to appear the same as a target image acquired with a higher or lower tube voltage. The normalized noise power spectra (NNPS) and standard deviation of the flat field images and the contrast-to-noise ratio (CNR) of the other images were calculated for the simulated and target images. The NNPS and standard deviation for the target and the simulated images were found to be within 2%. The CNRs of the target and simulated images were found to be within 4% of each other. The methodology successfully converted the images and can be used in observer studies to examine the impact of radiographic factors on lesion detection.