Digital chest imaging using a selenium detector. The impact of hard copy size on observer performance: a computed tomography-controlled study.

Rationale And Objectives: The authors compare radiologist detection performance under clinical conditions for assessment of the effect of size reduction on the diagnostic performance of digital chest images obtained with a selenium detector.

Methods: Sixty-five patients were examined with the digital system. The images were acquired without an antiscatter grid. Sixty-five posteroanterior life-size images (35 x 43 cm) and sixty-five posteroanterior minified images (56% of life size) were analyzed by three observers for detection of pulmonary, mediastinal, and pleural pathology, using computed tomography as the reference standard. The diagnostic value of life-size and minified images for the detection of these chest abnormalities was analyzed with receiver operating characteristic (ROC) methods.

Results: For the detection of the various abnormalities by all radiologists, the areas under the ROC curves with life-size images versus minified images, respectively, were as follows: pulmonary opacities, 0.78 versus 0.78; interstitial disease, 0.74 versus 0.75; mediastinal disease, 0.70 versus 0.72; and pleural abnormalities 0.72 versus 0.67.

Conclusions: There was no statistically significant difference between the radiologists' performance in detecting pulmonary, mediastinal, and pleural pathology with life-size versus that with minified (56% of life size) digital selenium chest radiography.