Digital imaging of the chest

The development of effective methods for producing digital chest radiographs is essential if the totally digital radiology department of the future is to evolve. Digital radiography of the chest is now possible with a variety of techniques. The most promising approach currently in clinical use involves the use of large-area detectors composed of photostimulable phosphors read with a laser to produce high-quality digital chest images. Image processing to modify contrast and latitude of the image display as well as enhancement of selected spatial frequencies and energy subtraction is possible with digital chest radiography. The wide exposure latitude of digital image receptors may allow useful images to be obtained with significantly smaller exposure doses than those required in conventional techniques and may also be used to compensate for inadvertent overexposure, eliminating the need for repeat examinations because of errors in exposure technique. Limitations of many current systems result from inadequate resolution provided by CRT display monitors. The production of hard copy images by laser printer on small format film overcomes this problem, allowing application of digital techniques for chest radiology to be incorporated into clinical practice with images comparable in spatial resolution to those of film-screen systems.