Densitometric measurements of lung nodules on chest radiographs.
A technique is described whereby embedded nodular densities appearing on chest radiographs can be densitometrically measured without the obscurring effects of anatomic structures. The technique consists of rear-projecting a light beam into a chest radiograph and an observe adjusting this beam until the lucency matches that of the nodule's appearance. The radiography is then removed, and the lucency is scanned and analyzed with a microcomputer. Calibration data using simulated nodules show a good accuracy in measuring size, contrast, and edge gradient.
D015502:Absorptiometry, Photon / Q000379:methods*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*