Comparison of the detectability of high- and low-contrast details on a TFT screen and a CRT screen designed for radiologic diagnosis.

RATIONALE AND OBJECTIVES

To evaluate the detection rate of fine details of a new thin-film transistor (TFT) grayscale monitor designed for radiologic diagnosis, compared with a type of cathode ray tube (CRT) screen used routinely for diagnostic radiology.

METHODS

Fifteen radiographs of a statistical phantom presenting low- and high-contrast details were obtained and read out with an Agfa ADC compact storage phosphor system. Each radiograph presented 60 high-density (high-contrast) and 60 low-density (low-contrast) test bodies. Approximately half the test bodies contained holes with different diameters. Observers were asked to detect the presence or absence of a hole in the test body on a 5-point confidence range. The total of 1800 test bodies was reviewed by 5 radiologists on the TFT monitor (20.8 inches; 1536 x 2048 pixels; maximum luminance, 650 cd/m2; contrast, 600:1) and the CRT monitor (21 inches; P45 Phosphor; 2048 x 2560 pixels operated at 1728 x 2304 pixels; maximum luminance, 600 cd/m2; contrast, 300:1). The data were analyzed by receiver-operator characteristic analysis.

RESULTS

For high-contrast details, the mean area under the curve rated 0.9336 for the TFT monitor and 0.9312 for the CRT monitor. For low-contrast details, the mean area under the curve rated 0.9189 for the TFT monitor and 0.9224 for the CRT monitor. At P <or= 0.05, no statistically significant difference could be detected between the 2 observational modalities for both (holes in high- and low-contrast disks) types of artifacts.

CONCLUSIONS

The TFT screen performs as well as CRT monitors for the detection of fine details in both high- and low-contrast environments. Further studies with images derived from clinical routine are necessary before safely using TFT monitors in clinical practice.