It was only a matter of time before digital radiography (DR) would begin to make inroads in medical imaging. Industry watchers estimate about 40 percent of x-ray rooms today are supported by digital radiography (including DR and computed radiography) - and because many are workhorses in the busiest of radiology departments, some even say we've reached the crossover point that more x-rays are being created digitally today than via old-reliable analog units, which will continue in action for many, many years to come.
A series of motivating incentives including more sophisticated picture archiving and communications systems (PACS), the evolution of flat-panel digital x-ray image capture technology that yields high-quality images at lower x-ray dose, as well as the economic imperatives for increased efficiency from overburdened clinicians all converged to drive adoption of DR systems at an ever-increasing rate.
DR systems, often designed to mimic the workflow patterns of a general radiography room, have proven their value whether deployed in a hectic emergency room setting or a demanding orthopedic clinic. While PACS is often considered pivotal to making the decision to install DR, there are institutions that have not yet completed that step, who find DR still to be appealing.
As institutions make their decisions about purchasing digital radiography solutions, they must consider their patient population to justify the increased expense these systems entail. For example, smaller hospitals or clinics may not have the patient volume that will offset the expense of the purchase of this equipment as general radiography studies are notorious in their low reimbursement rates.
Vendors large and small have worked to develop the capabilities of their offerings to address economic concerns as well as enhance clinical practice through improved image quality, and speed of acquiring images. There are many clinical settings where image acquisition speed assumes critical importance, such as intensive care units or emergency departments.
Bottom-line benefits include decreased operating costs due to reduced requirements for film, processing, chemicals and archiving space for film images, as well as the labor involved in managing all of those activities.
One of the other advantages to DR over film is that with a quick review of the digital image, if a patient needs to be repositioned, that activity can be accomplished more quickly. Therefore, the patient is not inconvenienced by having to wait to have film developed, and then another attempt to obtain the quality of image that is required.
Ralph Koenker, MD, director of radiology for Novato Community Hospital, a Sutter Health Affiliate in Marin County, Calif., speaks to the issue of efficiency enabled by their busy Philips DigitalDiagnost.
Novato Community Hospital accomplished 24,000 exams in 2000, and 36,000 in 2003, he says. During the same period, the facility reduced the number of x-ray techs from 11 in 2000 to 10 in 2003, and reduced their clerical positions by 0.5 FTE. While they no longer needed the number of file clerks to manage films at their original staffing levels, they were able to retrain those personnel to answer phones and schedule patients.
"In terms of overall efficiency, DR is much faster than film because it's a 30-second turnaround per image as opposed to three minutes for film," says Kroenker. "And CR [computed radiography] is the slowest, which is about four to five minutes for the tech." That is why they were able to take more x-rays with fewer technologists.
He describes that CR is no faster than film because of some of the quality control (QC) steps involved with having to package the file properly for a PACS. The other advantage of DR over CR is image size - with DR images being 3Kx3K and CR only 2Kx2K.
"Some DR units have problems with image burnout at sites where there is air and soft tissue, for example at the shoulder. With our units, that has not been a problem at all. In terms of dynamic range response curve, the ability to handle burnout, this system is very good in our opinion," he relates. Additionally, they have found that they have been able to use reduced x-ray dose, yet acquire the high quality they demand in their images.
Sutter Health has installed one of the DR units in an outpatient center to provide upright, horizontal and supine studies, which prove beneficial for ambulatory patients. The unit in the hospital has