Effects of luminance and resolution on observer performance with chest radiographs.
OBJECTIVE
To examine the combined effects of image resolution and display luminance on observer performance for detection of abnormalities depicted on posteroanterior chest radiographs.


METHODS
A total of 529 radiographs were displayed on a specially constructed view box at three luminance levels (770, 260, and 85 cd/m(2)) and three resolutions (100-microm, 200-microm, and 400-microm pixels). Each image was reviewed nine times by six radiologists who participated in this study. The abnormalities included nodule, pneumothorax, interstitial disease, alveolar infiltrates, and rib fracture. Negative (normal) radiographs were also included.


RESULTS
Receiver operating characteristic curves indicated that the effect of image luminance was greater than that of resolution. The detection of pneumothorax, interstitial disease, and rib fracture showed statistically significant differences (P <. 05) due to luminance. The detection of pneumothorax was the only abnormality with a statistically significant difference due to resolution. There was no evidence that luminance was related to image resolution for any of the abnormalities.


CONCLUSIONS
At a resolution of 400-microm pixels or higher across the field of view and a luminance of 260 cd/m(2) or more, primary diagnosis with posteroanterior chest radiographs is not likely to be affected by the quality of display.
Herron
J M
JM
Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15261-0001, USA.
Bender
T M
TM
Campbell
W L
WL
Sumkin
J H
JH
Rockette
H E
HE
Gur
D
D
D000704:Analysis of Variance; D003626:Data Display; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008027:Light; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging; D015588:Observer Variation; D011030:Pneumothorax / Q000000981:diagnostic imaging; D011446:Prospective Studies; D011650:Pulmonary Alveoli / Q000000981:diagnostic imaging; D012372:ROC Curve; D011856:Radiographic Image Enhancement / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D012253:Rib Fractures / Q000000981:diagnostic imaging; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging; D013997:Time Factors