X-ray exams once
seemed like a scene
from an old science
fiction movie

CR vs. DR detectors – and the inexorable march of progress

November 05, 2015
by Lee Nelson, Contributing Reporter
With the advent of computed radiography (CR) over two decades ago, and wireless digital radiography (DR) about 15 years ago, things have continued to change for the better when it comes to radiography — especially in the large, busy facilities. The speed of the procedures, the significant dose-reduction capabilities and better image quality are a few of the well-known benefits of digital X-rays. The vendors that make these systems and upgrades are continually working to improve them — so they’re more efficient, more robust, more portable — and hopefully, less expensive, enabling more facilities around the world to take advantage of their benefits.

“Since clinicians can now see images in less than five seconds, they can quickly assess a patient’s condition and begin appropriate treatment,” says Tim Sisco, director of cardiovascular and imaging services at Houston Healthcare. “Instant access to high-quality (DR) images enables us to take a huge step forward in patient care, especially for acute care patients in our ER and ICU.”

The tortoise and the hare
Houston Healthcare performs over 160,000 diagnostic imaging procedures a year at its two hospitals, one outpatient imaging center, an X-ray room in a cancer center and three urgent care clinics. “About 60,000 are X-ray exams, and of those, 50,000 are DR and 10,000 are CR exams,” Sisco says. He remarked that recently he thought he needed a second X-ray room, but DR allowed him to double productivity through a single room and take care of double the number of patients.


Tim Sisco

“It is twice as productive without replacing or building a second X-ray room,” he says. Houston Healthcare chose Carestream to install a fully automated, dual-detector system in its busiest X-ray suite, that handles emergency department and general radiology exams. The hospital also converted two existing portable imaging systems with DR detectors.
“You can take the portable DR to the patient’s bedside, and it’s much faster than using a CR cassette. You don’t have to walk away to process it, and since you can see the image as soon as you take it, you know if you have to repeat the study right on the spot,” Sisco says. For trauma cases, he says DR is a huge improvement in patient care because it allows the physicians to make decisions while the patient is still on the gurney.
“Previously, the physicians might have stepped away while the cassette was being processed, and when it was ready they had to go back to a workstation to be able to view the images,” he says. “It could take 10 to 15 minutes to process a cassette. Now they can view images in less than five seconds on the portable’s monitor and make decisions. That’s a tremendous advantage in the ED setting.”
At Dartmouth-Hitchcock Medical Center in Lebanon, N.H., Jason Spaulding, section supervisor, says, “Our first wireless digital detector was purchased in 2009 from Philips. It was first used in an outpatient environment, then moved to the emergency room, and we have not had to replace it, or any of our detectors. It’s a testament to the care our technologists take with the equipment,” Spaulding says. Today the facility performs an annual total of 207,000 imaging exams, of which approximately 85,500 are DR studies and 15,000 are CR studies.


Jason Spaulding

The staff is very pleased with the speed and ease of the wireless DR detectors. “We took the upgrade path to bring speed and better delivery of care to those in the ED. A big part of the driver to go to DR was the speed of image processing in the trauma setting. These are the first images we get and time is of the essence, as you can imagine. Not only are they fast, the image quality is superior,” Spaulding says.
Howard Sanford, diagnostic imaging operational manager at El Camino Hospital, Mountain View, California, says the facility performs about 125,000 total imaging exams a year. About 65,000 of those are DR X-ray procedures, just a handful are CR. “We’re really all DR. We went DR hospital- wide about 5 years ago, and a ROI was not an issue, not part of the business plan. We were solely focused on patient care and DR gives our radiologists and patients the best of both worlds: speed and quality images at a lower dose,” Sanford observes. “We also have two AMX-4s that were upgraded to DR located at a different campus. For those we chose Carestream DR kits.”
What’s out there in CR and DR upgrades (and what about film)?
There is a consensus among most end users and OEMs that CR will stay around a while longer, possibly another decade. There continues to be a place for it in all sizes of medical facilities. But DR already reigns supreme and continues to grow as radiography goes fully digital. And yes, there are providers in the United States that still use film.
“We still do a decent volume in the U.S. with analog among end users outside of the hospital setting,” says Chris Scotto DiVetta, fixed radiography segment leader, X-Ray, at GE Healthcare. “Our Proteus XR/a is a tried and true system, and it does sell in the United States. These low workflow customers start with analog and know they can upgrade to digital if the need arises. The machine also does quite well in the global markets in India, China, Asia Pacific and Africa.”
GE is not in the DR upgrade kit business, but is very big in full DR systems. Konica Minolta is one of the manufacturers that continue to provide film to meet the needs of the analog market, and Fujifilm does as well. Rob Fabrizio, director of marketing and product development for Fujifilm, estimates the company has about 15 to 20 percent of the film market in the U.S., but that, as part of their total sales, “is barely a blip on our radar screen.”


Helen Titus

The ability to upgrade quickly from CR to DR happened for many end users when Carestream launched its first DRX-1 wireless portable detector in 2009, says Helen Titus, worldwide X-ray and ultrasound solutions director for Carestream. “Our detector was the same form-size, the same shape as the CR cassette, and that made upgrading very easy, you could do it in half a day. Today, cassette-size wireless DR detectors that fit in the CR slot are pretty much a standard product,” she says.


Stefan Mintert

Stefan Mintert, marketing and portfolio manager at Philips Healthcare in Amsterdam, was able to speak to the preferences of end users in Europe. And he says going with a CR or DR upgrade depends on the country you’re looking at. “If you look at northern Europe, such as Scandinavian countries, with the most sophisticated health care systems, you won’t find many hospitals that don’t have DR already,” he says. “The look is similar in the Netherlands and a big part of Germany.”
Other parts of Europe are using CR. “Developing countries such as those in Africa still use film. Some areas of the world have never offered X-rays to their patients. Some do not have the training, money, clinics or staff. But as they progress, the medical offerings will grow,” he adds.
“CR is still a very good alternative because of its digital image and lower cost,” Titus says. “CR is still growing when we are talking about a global market. For the U.S. market, CR is declining since there is a higher conversion to DR.” Spaulding of Dartmouth-Hitchcock says his facility still uses CR for some portable Xray work, and some individual images that are hard to get with fixed DR rooms like shoulders and views of the patella. Fabrizio believes that CR is going away fast. “For the most part, customers are not looking for CR. They only buy CR to complement their DR purchases,” he says.


Viola Fernandes

On the other side of the debate, Viola Fernandes, radiography product manager at Siemens Healthcare, sees CR technology slowly declining. “If a CR system does the job, then there’s no reason to spend to improve it,” she notes. Her company isn’t in the business of selling CR or DR upgrade kits. However, Siemens partners with Konica Minolta to provide digital upgrades for Siemens’ systems, if that’s what a customer wants. The Konica Minolta partnership also enables Siemens to be a player in large transactions where the client wants both new, full DR systems together with upgrades to some of their existing analog systems.
Going mobile…
With the price tag of a DR detector alone in the neighborhood of $80,000 to $100,000, DR for many people stands for “Don’t Rest.” To optimize an investment in DR, providers want to keep the wireless detector working throughout the day. The key to doing that cost-effectively is having a system with a detector and a mobile wireless access point so the DR detector can be used in any rad room, or with mobile X-ray equipment.
For example, Canon, through its Virtual Imaging division, offers the RadPRO Delinia digital X-ray acquisition cart. “It’s a mobile cart that comes with a wireless DR detector that works with any existing fixed or mobile X-ray generator, so you can use it in multiple areas of a facility,” says Mark Anderson, product manager for Virtual Imaging.
Tom Spees, vice president of sales for Richardson Electronics, says his company offers the EZ2GO, a DR system with three components: a detector, an operating tablet that is a wireless access point, and software for the workstation. “This makes it easy to take the detector and tablet anywhere in a facility where the system is needed,” he observes. Fuji makes a DR system with a laptop as the access point, and Spees says, “Expect to see more fully mobile DR systems like these at this year’s RSNA.”
The other solution is onboard image storage capacity. These types of detectors can store from 100 to 400 images. The result is something of a cross between CR and DR: the detector needs to go to a reader where the images are downloaded, but because it’s DR, you get the advantage of low-dose capability.
Reduction of dose and better image quality
The reason many medical facilities are switching to DR, and sometimes from film to CR, is to get better image quality and to reduce radiation dosage given to patients during the procedure. Agfa Healthcare received clearance from the FDA last year to claim its DR systems reduced dose radiation up to 60 percent compared to film. And you will find all the OEMs citing dose reductions of 40 to 60 percent, or more, with DR.
“We have affordable low dose in CR as well as DR,” says George Curley, senior sales marketing manager at Agfa, “and we have new CR systems that give you better image quality at a lower dose.” However, he admits, customers are moving from CR to DR to gain efficiency, especially in fast-paced medical centers. “It helps managers to justify the initial expense of going to DR if you can get more efficient on 70 percent of all your exams,” Curley says. “That’s huge, because it is the biggest volume of procedures.”


Guillermo Sander

Dose reduction is a double-edged sword, according to Guillermo Sander, digital radiography, senior product manager at Konica Minolta Medical Imaging. “Due to the higher image quality of DR, the dose can be lowered more with DR than with CR,” he explains. But lowering the dose is a trade-off: “Radiation dose is a result of the kVP. A higher kVP delivers more dose and less image noise (higher image clarity), while a lower kVp delivers less dose and more image noise (lower image clarity). Dose varies due to differences in image quality from the different available systems as well as the difference across radiologists and their acceptance of noise in the images. There is a point at which the image noise renders the study unreadable.”
Spaulding of Dartmouth-Hitchcock says the dose reduction capability of DR is a boon when it comes to imaging patients with larger body mass. In the past, you would have to increase the radiation level for a large patient to get an acceptable image. “With DR, you can use a lower dose, or use an older portable X-ray with lower energy and still get a good image,” he says.


Tom Spees

Imaging processing algorithms and GUIs
One factor that differentiates one DR detector from another is the image processing algorithm that is loaded onto them. This algorithm is each OEM’s “secret sauce,” says Spees. It takes the raw data from the X-ray bombardment and creates the initial image. Think of an iPhone and Android phone as an analogy — it’s the software that makes each smart phone “smart.” DR vendors also add a second level of software that lets the user, at the workstation, manipulate and fine-tune the image even more. This is the GUI, or graphical user interface. This can be modified by the end user so the baseline image for a chest X-ray, for example, is always the same, and the way the radiologist prefers. Then any indications or anomalies are easier for the radiologist to see.
Who’s who on the OEM side?
The manufacturing process that creates a DR detector is sophisticated and expensive. That’s why only a handful of companies worldwide have made the investment to be in the detector business. According to Rick Colbeth, general manager and vice president of imaging products for Varian, his company has the largest portfolio of flat-panel detectors, covering the full range of X-ray imaging modalities, not just digital radiography (DR). In radiography, all their detectors are DR — they make no CRs. Varian does not sell direct to the end user. They customize each detector to order, so what each vendor sells is unique.
Another leading supplier of DR detectors is Trixell, headquartered in France. It’s a joint venture among Thales, Siemens and Philips, with Thales owning a majority interest. Thales is a leading manufacturer of electronic devices, particularly image intensifiers, and this joint venture was a natural fit for the company. Richardson Electronics, for one, buys its detectors from Trixell. A third OEM that private labels DR detectors is Vieworks from South Korea. Like the others, it adds custom features to the detectors to create a proprietary product.


George Curley

What are companies working on for the future?
When it comes to DR technology, manufacturers are working to make them lighter, less fragile, easier to use and more resistant to fluids. “Just like in the car industry where they went from metal chrome to crumple zones, that’s what vendors are doing with detectors and such, with more shock resistance. They are also making them lighter and easier to handle,” says Curley.
With Fujifilm’s exclusive Hydro AG coating on the FDR D-EVO II, the detector becomes, the company claims, 99.99 percent effective against bacteria. The pending patent boasts it is, “100 times more effective than traditional silver ion coatings and 10,000 times more effective than surfaces with no coating.” Anderson says that a detector’s IPX rating is becoming a big selling point. “IPX is essentially an industry-standard fluid resistant rating. Canon, as are many other companies, is working to develop detectors that have a good IPX rating — it’s something to look for now and in the future as a desirable feature,” he adds.
Siemens is working on developing value-priced X-ray systems without all the “bells and whistles,” so even the smaller clinics without big revenues can afford to bypass upgrading an older analog system to CR or DR and buy a brand new digital system, Fernandes says. DiVetta says GE is working on VolumeRAD imaging with its DR systems, which he says is the first radiographic tomosynthesis product with a specific indication that offers improved detection and management of patients with lung nodules, compared to conventional radiography.
Titus sees the trend for X-ray systems and everything that goes with them as continuing to drop in price because of additional manufacturing capacity and more competition. Colbeth sees DR prices coming down as well, as the demand for DR grows. Higher order volume is creating manufacturing efficiencies and cost savings that Varian can pass along to its customers. They’ve also been able to reduce the cost of the internal electronics as well, while actually improving image quality — a trend that is happening across the industry. On the bottom line, Colbeth says, “the price for DR, in some cases, is close to that of a CR system.”