Conspicuity and uncertainty in the radiographic detection of lesions

Conspicuity refers to how well a given feature stands out from surrounding structures. While this concept is being used increasingly as a qualitative descriptor, attempts to express it in quantitative form have not been entirely successful. It is necessary to quantitate detectability and also to ascertain that the detected feature is indeed the one being sought. The author has introduced the concept of uncertainty, a quantity derived from false-positive rates. Experiments show that the resulting expression of conspicuity correlates well with the probability of detecting lesions on chest radiographs and may also be used to compare imaging techniques so as to determine their relative accuracy.