ABSTRACT
In this chapter, a simple figure-of-merit denoted the dose-normalized contrast-to-noise ratio (CNRD) is introduced to optimize the trade-off between image quality and radiation exposure in digital radiography. In the examples, the dose metric used for normalization is the air kerma incident on a patient. The two example tasks explored are those of distinguishing kidney from adipose tissue and a lung nodule from lung tissue. Results for a range of thicknesses of patient are presented (15, 20 and 25 cm). Although the approach is simplified, the predictions reflect the tube potentials used in clinical practice for abdomen and chest examinations. The limitations of the calculations and possible improvements are discussed.
