Study ties DR cost justification to steady patient volume

February 11, 2003

New research concludes that the high cost of digital radiography (DR) may not be justifiable unless a facility has a steady high patient volume. Then it can run the device at or near 100% productivity.Confusion persists as to whether to invest in

New research concludes that the high cost of digital radiography (DR) may not be justifiable unless a facility has a steady high patient volume. Then it can run the device at or near 100% productivity.

Confusion persists as to whether to invest in computed radiography (CR) and/or DR or continue to use conventional screen-film. The paper (J Digit Imaging 2003 Jan 21 [epub ahead of print]) presents a comparison of CR versus DR and screen-film in terms of workflow, technologist productivity, overall speed of service, and potential cost justification for imaging the chest in ambulatory patients.

"Cost justification for DR over CR appears to be tied predominantly to high patient volume and continuous rather than sporadic use patterns," said author Katherine Andriole, Ph.D., an assistant professor of radiology at the University of California, San Francisco.

The study found that a mean of 8.2 patients were moved through the analog chest room per hour, versus 9.2 using the CR system and 10.7 with the DR system. These figures represent a 12% increase in patient throughput for CR over screen-film, a 30% increase for DR over screen-film, and a 16% increase for DR over CR.

Measured time to image availability for interpretation is much faster for both CR (77%) and DR (80%) versus screen-film and 15% faster for DR over CR.

"We have done a poor job in radiology of documenting whether the technologies we use make an impact on healthcare," Andriole said.

But she stressed its importance. Technology assessment and validation is one reason, cost justification is another.

"This paper again confirms the superiority of CR/DR over conventional film in improving workflow and productivity," said Henri "Rik" Primo, director of information systems for Siemens Medical Solutions.

The study considered only outpatient chest exams, an application in which analog screen-film is easily applied. Examining these issues in more complex environments such as OR/ICU/ER settings, however, would show even more impressive results and confirm the superior value of these technologies, he said.

"While DR is more expensive than CR today, when DR is combined with a specialized radiographic stand that allows multiple projections without moving the patient, it will outperform CR and analog film from a workflow point of view, and even more important, from a quality of medical care point of view, specifically in ER departments," Primo said.

In these cases, the higher price of DR can probably easily be justified, he said.

In the near term, CR and DR will probably coexist as imaging modalities for PACS in their specific niches.

"DR will evolve to be the gold standard for outpatient and inpatient applications that require high throughput," Primo said.

CR will be a practical and cost-efficient solution for bedside examinations.

"Lightweight and economic DR detectors will also move in on this application segment and gradually replace CR," he said.