Digital radiography, which comprises both computed radiography (CR) and direct radiography (DR), has gained strong market acceptance as an alternative to film-screen X-ray. It eliminates file rooms and their related costs, boosts efficiencies by providing enterprise-wide image access via digital information systems and reduces the potential for error. But to truly maximize this technology, potential users must first determine which option-CR, DR or a combination thereof-is best for them.

Direct (selenium) and indirect (silicon, photostimulable phosphor and charge-coupled device) detectors fall under DR's umbrella, employing a closed system that captures and converts X-ray photons to a digital image. Like some DR systems, CR systems use photostimulable phosphor to replace traditional film inside the cassette. After the exam, the cassette is placed in a CR reader, where energy released by exposing the plate to a laser beam is collected and converted to a digital image. The primary functional difference between the technologies is that CR uses cassettes and requires the introduction of media into a reader, while DR has self-contained detectors and read-out mechanisms.

Although DR systems are typically priced higher than CR systems, the Centers for Medicare & Medicaid Services and private payers reimburse diagnostic X-ray services at the same price point regardless of the technology. Scrutinize your X-ray volume and service-line offerings when determining which technology-if not both-is best suited for your practice needs and locations.

The capability of DR and CR to deliver an image onto a picture archiving and communication system (PACS) has been a major advantage over traditional film-screen X-ray. This has been particularly noticeable in trauma and emergency department (ED) settings, where radiologists and referring physicians can see these images almost instantaneously after an exam.

Online access to X-ray images via PACS also improves patient care. In the analog environment, clinicians wait for film to be processed and transported. But in the digital environment of DR and CR, physicians can access the images regardless of their location. Case in point: the Yale-New Haven Hospital in Connecticut, offers CR and DR throughout its tertiary care academic medical center in outpatient and inpatient diagnostic radiology settings, its ED, intensive care unit, operating rooms and neonatal unit. The outpatient facility, which conducts primarily orthopedic and chest exams, has seen a 10 to 15 percent increase in patient throughput for X-ray studies. In the ED, the DR system's throughput has been key to patient care.

Patsy Twohill, emergency department manager at Yale-New Haven, has experienced firsthand the improved clinical care and increased physician and technologist satisfaction that DR and CR technology deployment can bring. Although her facility's physicians haven't expressed a preference for DR or CR regarding image quality or consistency, Twohill says the technologists prefer DR because they perform fewer steps during an exam. CR and DR provide consistent image quality, she says, and the anatomically based image processing yields an optimal image every time.

Additionally, the quality control (QC) software shapes the DR and CR user experience, and the processing algorithms can extend the diagnostic certainty of interpreting radiologists.

A radiology department should assess these areas before acquiring digital radiography:

-consistency of image appearance (for radiologist accuracy);

-image resolution (e.g., will the system support chest and extremity imaging equally well?);

-available processing algorithms at the technologist QC station and the radiologist diagnostic station (for extending diagnostic certainty);

-consistency of user interface and ease of use (for technologist and radiologist efficiency);

-prompt, accurate service and support; and

-lifetime cost (including return on investment and capital depreciation).

Both CR and DR can consolidate X-ray rooms, achieve greater throughput to meet high-volume needs, improve image quality and reduce retakes, lower the number of lost films and be an integral part of the digital diagnostic imaging record.

Radiologists, referring clinicians and patients will continue to demand digital radiography deployment. Your decision regarding which technology will best meet this demand should be based on its expected clinical utilization and the workflow patterns within your practice.

John Strauss is the director of imaging systems for FUJIFILM Medical Systems USA Inc., Stamford, Conn.