Clinical utility of computed radiography (CR) for the diagnosis of lung cancer

To clarify the clinical utility of computed radiography (CR) for the diagnosis of lung cancer, several kinds of image-processed CR images were compared with conventional radiographs (CXR). The images in the three patients with peripheral lung cancer were processed by the following six types: 1) processing close to CXR (plain CR), 2) wide latitude and high frequency emphasis (wide CR), 3) advanced high frequency emphasis (HE-CR), 4) lower frequency emphasis (LE-ES). In the two cases of hilar lung cancer, 1) plain CR, 2) wide CR, 3) CR tomographs similar to CXR tomographs (plain CR-TOMO) and 4) high frequency emphasized CR tomographs (HE-CR-TOMO) were processed. Twenty-six radiologists rated the image-processed CR images using a 5 point rating scale method. The following results were found for the evaluation of lung anatomy: almost all image-processed CR images were equal or superior to CXR; especially scores for plain CR were better than those for CXR in all anatomical structures studied; scores for ES were superior to those for plain CR in the bilateral main bronchi, left upper lobe bronchus and right paratracheal stripe; and scores for CR tomographs were better than those for CXR tomographs. In peripheral lung cancer, plain CR and ES were superior to CXR. Especially ES had the best scores. In hilar lung cancer, plain CR and CR tomographs were judged better than CXR and CXR tomographs. These findings indicate the usefulness of CR images for the diagnosis of lung cancer. (author)