Filmiess digital chest radiography within the radiology department

The technical purposes of this work were to develop improvements in the methodology for assessing the physical performance of CRT monitors and display controller systems and to explore image processing techniques to make soft- A nd hard-copy image quality visually similar. The clinical purpose was to determine whether, with proper image processing, softcopy presentations of digital chest radiographs could become equivalent to hard-copy for visualizing normal and pathologic features. The luminance characteristic curve, luminance uniformity, modulation transfer function, and noise power spectra of the CRT monitors as well as video waveforms of a display controller were measured. Posteroanterior and lateral chest radiographs were acquired by a dedicated thorax imaging system with a selenium detector and processed using a previously optimized algorithm for printing on film. A Laplacian pyramid filter was employed to compensate for the mid-to high-frequency contrast losses in the soft-copy presentation. Five chest radiologists directly compared the soft- A nd hard-copy presentations in eighteen patients with CT-proven pathologies. Based on 99% confidence intervals, the soft-copy images were preferred for seven of the fourteen anatomic categories and image contrast, and the hard-copy images were preferred for brightness and image granularity. There were no preferences for the depiction of pathologies, spatial resolution, and the remaining anatomic categories. After determining the physical properties of the CRT monitors, image processing operations can be defined to produce soft-copy renditions of digital chest radiographs that appear clinically equivalent to their hard-copy counterparts. The results indicate great promise of soft-copy displays for primary diagnosis to make digital radiography more cost-effective and to encourage additional development of flimless image interpretation and management in a PACS.