OBSERVER PERFORMANCE IN THE LOCALIZATION OF TUBES AND CATHETERS ON DIGITAL CHEST IMAGES - THE ROLE OF EXPERTISE AND IMAGE-ENHANCEMENT

Rationale and Objectives. To determine whether observer performance in the localization of tubes and catheters on computed radiography (CR) chest images can be improved by using an automatic image-processing al gorithm. Methods. Comparisons were made of CR hard-copy, CR soft-copy, and CR enhanced soft-copy images obtained with an image-processing al gorithm. The enhanced images used gray-level optimization and nonlinea r unsharp masking to emphasize the edges of the devices. Chest radiolo gists (n = 4), general radiologists (n = 4), and interns (n = 6) read 45 images that contained endotracheal tubes, pulmonary artery catheter s, and central venous catheters. Results. Chest radiologists had the s mallest mean interobserver localization variability (4 mm), followed b y general radiologists (6 mm) and interns (8 mm). Localization variabi lity was greatest for hard-copy images and least for enhanced soft-cop y images. Conclusion. Use of an automatic imaging-processing algorithm reduced localization variability and enabled the medical interns to p erform at approximately the same level as the chest radiologists.