Multi-institutional analysis of computed and direct radiography: part II. Economic analysis.

PURPOSE: To compare economic aspects of equipment configurations, productivity levels, and patient waiting times in the performance of computed radiography (CR) and direct radiography (DR). MATERIALS AND METHODS: The study received internal review board exemption status, without the need for informed patient consent. Data from four study sites were used to calculate the CR-DR crossover point (defined as the point at which the cost-effectiveness of DR equals that of CR) and CR-DR annual cost differentials. Analyzed variables included equipment and operating costs, examination volumes, and productivity. A program was developed to simulate patient arrival times, number of patient examinations, and patient waiting times on the basis of average annualized parameters for each of the four clinics. Sensitivity analyses were conducted to assess utilization rates and determine cost optimization. Utilization rates were compared with the number of excess long-stay CR patients (ie, patients who spent more than 30 minutes waiting in the radiology department prior to CR examination) and with the cost (per excess long-stay CR patient who waited more than 60 minutes) averted by using DR. RESULTS: Excess annual costs for DR over CR at the four sites ranged from $50,757 to $75,303. At extrapolated levels of economic penalties for long waiting times, the crossover point at which the DR cost became justifiable was when CR capacity utilization rates approached or exceeded 80%. CONCLUSION: In the current practice environment, with capacity utilization rates well below 80%, CR is likely to be a more cost-effective technology for the majority of general radiography providers.

Multi-institutional analysis of computed and direct radiography: part I. Technologist productivity.

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.

Surgical quality assurance in the Ischemic Optic Neuropathy Decompression Trial (IONDT).

The purpose of this article is to report the methods and results of the surgical quality assurance program associated with the Ischemic Optic Neuropathy Decompression Trial (IONDT). A surgical quality assurance committee developed and implemented a quality assurance program for a randomized clinical trial requiring surgical intervention. A surgical technique questionnaire was administered at two times during the study course, and maintenance of surgeon certification required submission and approval of a masked videotape of an optic nerve sheath decompression surgery by each study surgeon. Surgical quality was assessed through completion of surgical report forms and standardized, masked review of operative notes. Rates of compliance and intra- and interreviewer agreement were assessed for each aspect of the program. Twenty-five of 32 surgeons (81%) successfully completed and maintained certification. Item agreement varied from 21-92% among reviewers of satisfactory videotapes and 22-89% on unsatisfactory videotapes. Intrarater agreement for videotape acceptability was 11 of 13 (85%), and for specific surgical steps, 147 of 182 (81%). Operative notes were submitted for 123 of 125 (98%) patients receiving surgery. Interrater agreement on individual items ranged from 73-100%. Classification of individual items was identical on first and second review for 1285 of 1344 (95.6%) items. Overall agreement for individual reviewers was 93.8-97.8%. We conclude that use of a small peer review committee, which developed and oversaw a quality assurance program, allowed for consistent certification and monitoring of surgical performance. This in turn increased the credibility of the IONDT results, which demonstrated no difference in outcome between operated and unoperated groups of patients.

Accuracy of interpretation of CT scans: comparing PACS monitor displays and hard-copy images.

OBJECTIVE: The purpose of this study was to determine the relative diagnostic accuracy of radiologists in the interpretation of CT scans using a computer workstation in comparison with using film. MATERIALS AND METHODS: Four board-certified radiologists with extensive soft-copy experience interpreted 117 CT scans in four anatomic regions using films displayed on an alternator and images displayed on a four-monitor workstation. The radiologists were asked to interpret the scans in their usual fashion and were aware that both the time required to review the study and the accuracy of the reports were being assessed. The radiologists' diagnostic impressions were compared with those of a consensus panel and scored for accuracy. RESULTS: Soft-copy interpretation using computer workstations was found to produce statistically significant improvement in combined measurements of sensitivity, specificity, and overall accuracy for chest, brain, and chest-abdominal CT scans compared with film interpretation. CONCLUSION: PACS (picture archiving and communication system) offers radiologists the potential for improved accuracy in CT interpretation compared with traditional film-based interpretation.

Health effects and biological monitoring results of Gulf War veterans exposed to depleted uranium.

A small group of Gulf War veterans have retained fragments of depleted uranium (DU) shrapnel, the long-term health consequences of which are undetermined. We evaluated the clinical health effects of DU exposure in Gulf War veterans compared with nonexposed Gulf War veterans. History and follow-up medical examinations were performed on 29 exposed veterans and 38 nonexposed veterans. Outcome measures used were urinary uranium determinations, clinical laboratory values, and psychiatric and neurocognitive assessment. Gulf War veterans with retained DU metal shrapnel fragments were found to be still excreting elevated levels of urinary uranium 7 years after first exposure to DU (range for exposed individuals is 0.01-30.7 micrograms/g creatinine vs. 0.01-0.05 microgram/g creatinine in the nonexposed). The persistence of the elevated urine uranium suggests ongoing mobilization of uranium from a storage depot, resulting in chronic systemic exposure. Adverse effects in the kidney, a presumed target organ, were not seen at the time of the study; however, other subtle effects were observed in the reproductive and central nervous systems of the DU-exposed veterans.