Evaluation of cardiopulmonary devices on chest radiographs: digital vs analog radiographs

We compared digital and analog radiographs of the chest for use in detecting and evaluating a variety of cardiopulmonary devices in 40 patients. The devices included 23 endotracheal tubes, 21 Swan-Ganz catheters, 14 central venous pressure catheters, 11 prosthetic valves, 10 chest tubes, six pacemaker wires, and five intraaortic balloon pumps. Each patient had at least one device, with a maximum of five devices (average, 2.3). Forty digital/analog film pairs were compared by five radiologists, who assigned confidence levels for various judgments about each device. The results showed that there were no statistically significant differences in the identification of the devices except for prosthetic valves (all valves were detected on digital radiographs, compared with 62% on analog radiographs). The devices were detected on 96% of the digital radiographs and 90% of the analog radiographs. Although digital and analog radiographs were comparable for detection of most devices, the digital radiographs allowed greater confidence in the identification of the devices and in the identification of the tip and course of Swan-Ganz and central venous pressure catheters.