Diagnosis of gastric cancers: Comparison of conventional radiography and digital radiography with a 4 million-pixel charge-coupled device

PURPOSE: To evaluate the differences in accuracy and observer performance a t conventional radiography and at digital radiography with a 4 million-pixe l charge-coupled device (CCD) for the diagnosis of gastric cancers. MATERIALS AND METHODS: A prospective study was performed of 225 patients wi th suspected gastric cancer who were referred to our hospital from January 1997 through February 1997. One hundred twelve patients were examined at co nventional radiography and 113 were examined at digital radiography, and 24 and 27 patients had gastric cancer, respectively. Six radiologists interpr eted the images, with attention to tumor findings. They were blinded to the clinical details, and their interpretations were rated against those of th ree other radiologists who examined the patients and who were aware of the clinical information such as endoscopic features and/or histopathologic fin dings in biopsy specimens. Receiver operating characteristic (ROC) analysis was used to compare the differences in observer performance for the diagno sis of gastric cancers at conventional radiography and at digital radiograp hy. RESULTS: The overall sensitivity was 64.6% at conventional radiography vers us 75.3% at digital radiography (P = .287); specificities were 84.5% and 90 .5%, respectively (P = .011); and the positive predictive values were 53.1% and 71.3%, respectively (P = .036). ROC analysis clearly showed higher dia gnostic performance at digital radiography than at conventional radiography . CONCLUSION: The data demonstrate the high diagnostic value of digital radio graphy with a 4 million-pixel CCD for gastric cancers. The technique has co nsiderable potential as an alternative to conventional gastrointestinal rad iography.