Multi-institutional Analysis of Computed and Direct Radiography

PURPOSE: To assess whether it is feasible to measure and compare work-flow times across institutional variations, and to apply such a comparison to technologist productivity in the performance of general radiographic examinations with computed radiography (CR) and direct radiography (DR). MATERIALS AND METHODS: The study received internal review board exemption. Participants were informed about the study and willingly participated. Observational time-motion analyses were performed at four sites at which CR and DR are used concurrently. The time taken by the technologist for patient preparation, positioning, exposure, and postacquisition processing, and for the examination as a whole, was recorded. Data collected reflect unique elements at each clinical center, and no standardized work flow was imposed. Work-flow performance times were correlated with each site profile. Preliminary statistical analyses included examination of distributions of original and combined variables. Descriptive statistics were presented as means or frequencies, depending on whether the data were continuous or categorical. Continuous variables were compared by using the Student t test. Timing differences between CR and DR for each clinical center were compared, and all data were analyzed by using commercially available statistical software. RESULTS: For all four study sites, statistically significant total examination time differences were observed when comparing CR and DR (P < .001). The single step in the examination that was found to be the largest contributor to time difference was postacquisition processing, which accounted for 30%-100% of the total time difference between the two technologies. The most time-efficient sites were those that had in-room postacquisition processing capability and fully functional integration with the radiology information system. Investigators at two study sites compared times for two-view chest radiography only, and those at the other two study sites compared times for multiview general radiographic examinations. Only the results of two-view comparisons were reported for each site. CONCLUSION: Overall technologist time was significantly shorter when performing tasks associated with DR than when performing comparable tasks associated with CR, a difference that appears to result largely from technology configuration, staffing, and patient management.