Density dependence of signal detection in radiographs.
We report results of the variation of signal detectability with radiographic film density for Lanex screens and four different x-ray films. We found that maximum signal detectability occurs near (but not precisely at) the maximum slope of the characteristic curve. We interpret our results using a model that includes film gamma quantum noise, film granularity, and an intrinsic observer contrast threshold.
D005069:Evaluation Studies as Topic; D011859:Radiography / Q000379:methods*; D014962:X-Ray Film