Low-voltage digital selenium radiography: detection of simulated interstitial lung disease, nodules, and catheters--a phantom study.

Purpose: To compare three tube voltages in digital selenium radiography for the detection of simulated interstitial lung disease, nodules, and catheters.

Materials And Methods: Simulated catheters, nodules, and ground-glass, linear, miliary, and reticular patterns were superimposed over an anthropomorphic chest phantom. Digital selenium radiography was performed with different tube voltages (70, 90, and 150 kVp). Hard-copy images were generated. Detection performance of five radiologists was compared by using receiver operating characteristic (ROC) analysis involving 54,000 observations.

Results: The detection of ground-glass, linear, miliary, and reticular patterns over lucent lung and of nodules equal to, smaller than, and larger than 10 mm increased when 70 kVp and/or 90 kVp was used. However, only the reticular pattern was significantly better detected at lower peak voltage (P <.05). Simulated catheters and nodules over the mediastinum showed smaller areas under the ROC curve at lower peak voltage. These results were not statistically significant (P >.05).

Conclusion: The diagnostic performance of digital selenium radiography at lower peak voltage is at least as good as that at higher peak voltage for interstitial lung disease over lucent lung. Performance is equivalent for nodules and catheters over obscured chest regions at lower peak voltages compared with that at 150 kVp. Our results implicate that the use of high-voltage technique in digital selenium radiography should be reassessed.