Assessment of radiological image quality by redundancy

The relationship between the subject contrast and the total image performance of a radiograph can be assessed by a single number. In this study, the radiological image quality containing object information in two screen-film systems was assessed by the redundancy, C(Y). The quantity C(Y) in the LTII-QS system has a lower value at low subject contrast but a higher value at high subject contrast, compared with the LHII-RX system. The value of C(Y) is affected more by the radiographic mottle of the system at low subject contrast and more by the MTF of the system at high subject contrast. (author)