Indiana University looks at DR and CR from all points of view in their 350 bed University Hospital.
In the summer of 2000, Indiana University Hospital (IUH),
Indianapolis, IN, became one of the first facilities in the country
to install a digital radiography (DR) system. IUH is a 350-bed
hospital that is part of the Clarian Health Partners hospital
system. A year earlier, the hospital decided it needed to replace
outdated x-ray equipment in its chest exam area. Radiologists and
hospital administrators agreed that the timing was right to convert
to a digital capture system that would integrate well with the PACS
(picture archiving and communications system) that is planned for
installation by the end of 2001.
The hospital had successfully installed several computed
radiography (CR) systems but decided to evaluate the new DR
technology. A DR system would offer even greater productivity
improvements and the potential for higher image quality.
DR describes projection radiographic systems that capture an
image with an embedded detector. That image is then read
electronically to produce a digital image. Image files are viewed
and adjusted, as needed, by technologists to ensure optimal image
quality prior to releasing the image. Images can be routed
automatically to PACS systems for soft copy review by radiologists,
or can be transmitted to local or remote sites for review or output
Several different technologies have been applied in DR systems.
Direct detectors automatically convert x-ray photons into
electronic signals and produce precise signal profiles and
resolution. Indirect detectors have an added step: they first
convert x-rays into light, and then convert the light to electronic
signals. In the process, light scatter tends to degrade the signal
profile and resolution.
IUH product selection
Dewey J. Conces, Jr., MD, Clinical Director of Radiology at IUH,
assumed responsibility for evaluating and selecting the DR
equipment (figure 1). At the 1999 Radiological Society of North
America meeting, he investigated systems, interviewed vendors, and
viewed sample images. He then reviewed charts of Detective Quantum
Efficiency (DQE), Modulation Transfer Function (MTF), and Nyquist
frequencies for several different DR technologies.
"After reviewing the scientific studies and looking at the
images, I determined that the direct detector technology held clear
advantages," notes Dr. Conces. "The higher Nyquist frequency and
MTF found with direct detector technology enhance visualization of
fine detail and provide superior imaging performance."
Since several companies market the direct-detector technology
selected by Dr. Conces, Stanley Metzger, administrative director at
IUH, assumed the task of selecting a vendor.
"In my mind, the expertise and resources of the vendor are as
important to a successful implementation as the quality of the
technology," he said. "This is a long-term investment for the
institution. We selected Kodak because it was the only vendor that
offered a history in imaging, long-term stability, excellent
service and support, and the best technology available."
The hospital purchased and installed a Kodak DirectView DR 5000
(Eastman Kodak, Health Imaging Division, Rochester, NY).
Benefits of DR at IUH
Dr. Conces is convinced that the DR 5000 system has improved
image quality. "After six months of use, we can confirm that the
Kodak DR 5000 system provides greater clinical detail than our
previous film-screen system."
In addition to providing enhanced image quality, the DR system
has also increased productivity. At IUH, patient throughput has
increased 60% since the installation of the DR system, according to
Metzger. He attributes this increase to the system's 10-second
preview and 35-second cycle time speed (figure 2), in addition to
the time saved by the elimination of processing and related
activities for film or CR cassettes.
Another feature that saves time is the fact that exams can be
taken in the order that requires the least patient movement. When
working with film, technologists usually capture views in a
prescribed order so that they don't "lose their place."
"The ability for a technologist to capture a digital image,
select a patient's name on the monitor, and perform quality control
on the image in seconds is a revolutionary step forward," Metzger
reports. "In addition, technologists don't need to leave the
patient to process cassettes or check the images--it's all done at
the system's operator console. And that's a tremendous advantage as
Staff training and support
As with any leading-edge technology, training and support are
critical elements to a smooth implementation.
"It took about a week to get familiar with the equipment and the
process. After several weeks, our technologists had forgotten all
about film and processors," Metzger observes.
Training on the DR system takes just a few hours for
technologists. Since patient positioning is the same, technologists
just need to learn the screen commands on the operator console. The
DR 5000 offers an easy-to-use interface that was designed with
customer input, so all terms and phrases are familiar to users.
Since the screen commands are customized to each facility's exam
process and naming convention, the technologists continue working
with the same terms they have used before. For example, one
hospital might use the term "accession number" while another uses
"patient ID number."
The specific views most commonly included with chest studies are
preprogrammed as well, so the screen prompts the technologist with
the views that are to be captured. As each view is captured, a
thumbnail view of each image is displayed on the screen.
Kodak also provides online monitoring of the DR system, which
allows off-site engineers to detect and correct any technical
issues before they can cause problems.
Part of an overall digital plan
While many facilities are still evaluating the merits of DR
technology, Dr. Conces and Metzger both believe it fills an
"Converting the radiology department to a digital platform
requires implementing either CR or DR technologies, or a mix of
both, as we have chosen," says Metzger. "CR offers flexible digital
capture at a reasonable price. As such, it's ideal for portable
exams, such as in the Emergency Room and Intensive Care Unit, and
other low-volume areas."
He also believes that DR technology has broader applications.
"We believe that the gains in productivity and image quality that
DR offers in high-volume environments offset its current price
Metzger is satisfied with the choice IUH made for their
radiology department. "Kodak's DR system offers an excellent
combination of image quality and productivity in a digital capture
platform," he explains. "We believe this is a compelling package
for any progressive health care institution."
The installation of the DR system at IUH has been so successful
that a second Kodak DirectView DR 5000 system has been installed to
perform chest radiographs at the 775-bed Methodist Hospital, the
largest facility in the Clarian Health Partners network.