[Evaluation of diagnostic accuracy of CRT monitor display for personal computer in the detection of small lung nodules: with particular emphasis on comparison between JPEG and wavelet compression].
OBJECTIVE
To compare observer performance on cathode-ray-tube(CRT) monitors for personal computers with that on conventional radiographs in the detection of small lung nodules.


METHODS
Fifty-eight normal chest radiographs and 58 chest radiographs with a small lung nodule were selected. Ten radiologists examined the original conventional films on a viewbox and digitized (8 bit) uncompressed and compressed images of the same patient on a color CRT monitor with a matrix of 1,600 x 1,200, and rated the presence of lung nodules with a five-level scale of confidence. The methods of compression used in this study were the JPEG and wavelet methods, with compression ratios of 6:1 and 15:1. Results were analyzed by receiver operating characteristic methods.


RESULTS
There was no significant difference between film and digitized uncompressed and compressed images obtained by the JPEG and wavelet methods with a compression ratio of 6:1. No statistically significant difference was detected between film and digitized image with wavelet compression at 15:1. However, detection was less accurate on digitized images with JPEG compression at 15:1.


CONCLUSIONS
Digitized (8 bit) uncompressed and compressed images with a compression ratio of 6:1 are acceptable for the detection of small lung nodules. Digitized compressed images at a compression ratio of 15:1 are also acceptable when the wavelet method is used.
Kihara
Y
Y
Department of Radiology, Niigata University Faculty of Medicine.
D003626:Data Display / Q000592:standards*; D006801:Humans; D008838:Microcomputers; D012372:ROC Curve; D013902:Radiography, Thoracic / Q000592:standards*; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*