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 pe rformance under clinical conditions for assessment of the effect of si ze reduction on the diagnostic performance of digital chest images obt ained with a selenium detector. METHODS. Sixty-five patients were exam ined with the digital system, The images were acquired without an anti scatter grid, Sixty-five posteroanterior life-size images (35 x 43 cm) and sixty-five posteroanterior minified images (56% of life size) wer e analyzed by three observers for detection of pulmonary, mediastinal, and pleural pathology, using computed tomography as the reference sta ndard, The diagnostic value of life-size and minified images for the d etection of these chest abnormalities was analyzed with receiver opera ting characteristic (ROC) methods. RESULTS. For the detection of the v arious abnormalities by all radiologists, the areas under the ROC curv es 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 statisticall y significant difference between the radiologists' performance in dete cting pulmonary, mediastinal, and pleural pathology with life-size ver sus that with minified (56% of life size) digital selenium chest radio graphy.