title: Contrast gradient and the detection of lung nodules.
abstract: The effects of edge gradient and blur on the detection pulmonary nodules were studied, using a test series of 175 artificial nodules on 30 chest films. The nodules were of homogeneous texture, about 1 cm in diameter and had a mean contrast of .12. Six observers viewed the film set, scoring both location and confidence. The sensitivity or the probability of a true-positive response was linearly related to the blur and a modified ROC analysis resulted in a family of ROC curves with the index of detectability monotonically decreasing with increased blur.
mesh_terms: D005069:Evaluation Studies as Topic; D005189:False Positive Reactions; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D011336:Probability; D011856:Radiographic Image Enhancement; D013679:Technology, Radiologic