Fluoroscopy is a solid technology finding new applications in interventional work such as stomach stapling, esophageal stricture dilation using balloons and coupled with CT for back pain management, as well as outside of radiology in gastroenterology. On the horizon, flat-panel detectors could increase fluoro’s flexibility by allowing operators to capture a single shot to magnify for viewing, saving both time and radiation dose. u Fluoroscopy is a tried-and-true imaging method in a mature market, but that does not mean the market is not branching out. Traditional fluoroscopy is commonly used for a variety of studies where real-time imaging is critical, such as swallow studies and examinations of the gastrointestinal tract. But the technique is branching out, becoming more common in such specialty areas as bariatric procedures and interventional work. u This branching out is critical to the health of the field, as some procedures that were previously the exclusive territory of fluoroscopy are increasingly being claimed by MRI and CT. New applications and new equipment features will help the fluoroscopy market flourish. It is certain, though, that every hospital will continue to need fluoroscopy to handle cases that demand a simpler imaging modality, real-time imaging, or a bedside physician location.
A Mature Market
According to an April 2002 report by industry analysts Frost & Sullivan, (San Jose) the current portfolio of fluoroscopy equipment vendors is satisfying market demand nicely, with replacement sales the primary outlet for new-equipment sales.
These findings are borne out by the experiences of Niral Patel, segment manager for fluoroscopy for the x-ray and angiography division of Siemens Medical Solutions (Malvern, Pa). “The general fluoroscopy market has shrunk in the last 4 years; it is becoming a replacement market,” he says. But he does not anticipate fluoro giving up much more of its ground. Some hospitals with capacity for and a history of four fluoroscopy rooms may be able to get by with only two or three such rooms thanks largely to the increased use of MRI and CT for diagnostic procedures.
“A lot of things have moved into endoscopy and CT,” he says. However, Patel believes that “somewhere, [the market] has to stabilize; [hospitals] have to have at least one fluoroscopy room.” He anticipates that future growth in the fluoro market will come as products allow easier and more comfortable use of the technology.
Traditional Fluoroscopy
A hallmark of traditional fluoroscopy has been its ability to change with the times. Stewart Markowitz, chair of the department of radiology for Hartford Hospital (Hartford, Conn), notes that fluoroscopy was “invented for doing barium and upper GI work,” functions that were replaced largely by endoscopy in the early 1990s. Next, radiologists added fluoroscopic evaluations of the small bowel to their repertoire, a procedure that has been replaced mostly by CT scans. “We’ve been pretty creative” in finding new uses for fluoroscopy as older uses are supplanted, Markowitz says.
Currently, Markowitz sees conventional fluoroscopy used in a variety of applications, most of which involve ascertaining the placement of exogenous items such as needles and catheters or studies that involve viewing motion in real time. Examples include swallow studies, which are becoming more prevalent in an aging population; evaluation of surgical leaks; evaluation and manipulation of enteric tube placement, catheter placement, and epidural needle placement; defecography in cases of chronic constipation; and infertility studies. “Fluoroscopy remains a simple technology,” Markowitz says, explaining that its simplicity allows the physician to remain by the patient’s side to provide comfort and explanation, something that is not possible with more complex imaging procedures like MR and CT.
The Siemens Medical Solutions Axiom Iconos R200
This relatively simple technology is one that continually finds new uses and applications. “[Fluoroscopy] is a modality that is not going away,” Markowitz says. He has seen a rise in the number of bariatric cases, those extremely overweight patients who seek stomach-stapling surgery as a last effort at weight loss. Fluoroscopy is an appropriate imaging method to evaluate staple placement, especially for these patients who may be too large to fit into an MR or CT scanner. A variety of vendors is expanding their fluoroscopy equipment to handle extra-large patients, with tables that can handle 400- to 500-pound patients. It is likely that these products will one day accommodate even larger patients. Such cases will probably increase as the number of morbidly obese Americans rises.
Markowitz also finds that fluoroscopy is expanding into interventional work. It is especially appropriate for less complex procedures such as esophageal stricture dilation using balloons, Markowitz says. This sort of simple procedure may not require the use of an expensive and complex system like MRI or CT, and the ability of the physician to stand beside the patient can be comforting.
Markowitz notes that other specialties outside of radiology are increasingly making use of fluoroscopy, such as the work done by gastroenterologists performing endoscopic retrograde cholangio-pancreatography (ERCP). ERCP, a procedure that allows viewing of the duodenum, the gallbladder, and related ducts, accounts for a significant percentage of use of the fluoroscopy rooms at Hartford Hospital. And Markowitz expects that fluoroscopy will continue to find new uses and adapt to changes in imaging needs. “We’re building on what we’ve already done,” he says.
CT Fluoroscopy
As fluoroscopy increasingly moves into interventional work, it is often combined with other modalities to achieve the advantages of both. This is the case with CT fluoroscopy, which combines the contrast and special resolution of CT with the real-time imaging capabilities of fluoroscopy. The modality typically allows for more accurate placement of needles and catheters as well as quicker procedure times.
At Johns Hopkins Medical Center (Baltimore), the CT fluoroscopy equipment can acquire three slices and display each at a speed of 13 frames a second, for a total of 39 frames a second. Two operational modes are available: a continuous mode, which offers real-time imaging, and an intermittent mode, which can provide spot images similar to those of conventional CT. The intermittent mode produces smaller radiation doses for both patient and operator, so it is the first choice for most routine interventions. Other methods for reducing radiation exposure, such as use of lead aprons and shields and use of needle holders, will also significantly reduce the radiation exposure of the physician. The facility logs about 2,500 CT fluoro procedures annually.
The Siemens Axiom Aristos FX
This combination modality has found a wide range of applications, says Kieran Murphy, director of interventional neuroradiology at Johns Hopkins. One such procedure is the injection of steroids or local anesthesia into the facet joints (the joints that stack the vertebrae) in the treatment of back pain. The clear, real-time images of CT fluoroscopy mean more accurate needle placement in less time, resulting in less patient risk and less anxiety for the physician and patient. Murphy also uses CT fluoroscopy to help navigate intraventricular spaces in the brain and when injecting bone cement in cases of pelvic hip fracture.
Murphy particularly recommends CT fluoroscopy for radio-frequency ablation of osteoid osteoma, a painful bone lesion affecting primarily young patients. In these cases, an RF probe is inserted into the lesion and ablation performed to reduce pain. CT fluoroscopy allows the radio-frequency probe to be placed much more quickly and accurately in these procedures. Anesthesia time for these cases has been reduced approximately 50% by using CT fluoroscopy; Murphy and his colleagues have used this method to treat osteoid osteomas in various locations within the patient. Patients often find that they are able to discontinue the use of pain medications within a month after the RF ablation procedure. A study of such procedures, coauthored by Murphy, appears in the March 2003 issue of the Journal of Vascular and Interventional Radiology.
“I’m amazed it hasn’t caught on more widely,” says Murphy of CT fluoroscopy. He notes that successful CT fluoroscopy is dependent on the ability to angle the gantry, a feature that caused Johns Hopkins to select its Toshiba America Medical Systems (Tustin, Calif) machines. Adding fluoroscopy to a CT machine is an easy and cost-effective step. “It’s like [adding] an air bag to your car,” he says. This contrasts with other combinations, such as MR fluoroscopy, which is not widely available and is inappropriate for some patients such as those with pacemakers. CT fluoroscopy is more flexible. And Murphy expects continued growth in the CT fluoroscopy field fueled by new applications.
Different Around the World
Differences in the use of fluoroscopy do not just occur among hospitals and modalities; they also occur around the world. One difference is the location of the operator. In the United States, the predominant method of operation is “side by,” in which the user stands beside the patient to operate the fluoroscope. However, the United States is unique in this preference, making it necessary for companies that serve global markets to offer other options. “The rest of the world does remote,” says Don Volz, business unit director for x-ray vascular for Toshiba. Toshiba’s Ultimax system accommodates these preferences by incorporating both “side by” and remote operation.
Hybrid Imaging PET/CT Scan (center) and Virtual Simulation Tools (right)
“Remote fluoroscopy is not catching on in the United States,” says Steve Dahlquist, vice president for global sales and marketing for Del Global Technologies’ Medical Systems Division (Franklin Park, Ill). Under the Villa brand name, Del Global Technologies has a significant worldwide presence, especially in Italy, so accommodating preferences for remote operation is a priority. Dahlquist also finds that other equipment specifications are different for the worldwide market. This includes tables with a smaller footprint than that common in the United States but larger image intensifiers, with 16-inch image intensifiers being common for the global arena.
Integrating Data
Some of the newest improvements in fluoroscopy address not the imaging modality but the way data are shared among systems and accessible to physicians and technologists. Siemens offers “multimodality viewing,” which Mark Lothert, segment manager for interventional radiology for Siemens, says allows tableside viewing of previous CT and MRI data from the hospital picture archiving and communications system (PACS), as well as integrating vital sign data. Similar functionality is available on the EasyDiagnost Eleva from Philips Medical Systems (Bothell, Wash). Thomas Stopfkuchen, business manager for RF, North America, explains that Philips uses “multimodality software” to pull CT and MR images from the PACS, allowing for a tighter integration between RIS and PACS and the fluoro room. “We’re making information seamlessly available,” Stopfkuchen says. The ability to access archived images and patient data will improve both workflow and patient care.
Workflow improvement is at the heart of many of the recent developments in fluoroscopy. “Our main goal is to improve workflow so patients can get in and out of the room,” Patel says. One example of this is “one-click autoprogramming,” a feature that allows technologists to select from preset parameters for certain patient categories, such as bariatric or pediatric cases. These presets allow for “less thinking on the technologists’ and radiologists’ part,” Patel says, allowing professionals to concentrate more on interactions with patients.
A similar feature is available on the EasyDiagnost Eleva from Philips, says John Steidley, vice president of cardiovascular x-ray. He explains that information on system preferences will be pulled from the RIS, with Philips working with each hospital to develop and program its own preferences for each type of procedure. Initial presets will come from data gathered from clients worldwide. Presets will differ from region to region, with the initial data for North America different from those for Europe, for example.
Future Trends
On the horizon, fluoroscopy is poised to become more flexible. One improvement dawning is the addition of flat-panel detectors to RF systems, something that Toshiba is testing through a handful of worldwide clinical trials. Volz comments that the resulting images would be “like instantaneous film; the spatial resolution is nearly identical to that of film.” This would allow operators to capture a single shot that could then be magnified for closer viewing, which means faster imaging with lower overall radiation.
Other vendors are eyeing flat-panel technology but a bit further out on the horizon. “The future [of flat panel in conventional fluoroscopy] is quite some time out; we have to make it cost-effective,” says Siemens’ Patel. However, flat-panel detectors are making inroads in other specialties; Lothert notes that the technology has been available from Siemens in the cardiac arena for more than a year, and the company hopes to introduce flat panel for interventional vascular work at RSNA this fall.
Combination systems, such as those that combine fluoroscopy for angiography with CT or MRI, are gaining in popularity. “We see a growing need for the combination of modalities,” says Siemens’ Lothert. He cites Siemens’ Myabi, a system with its roots in Japanese experience with a variety of cancers, as an example of a product that serves a niche market but improves workflow by allowing multiple imaging procedures to be completed in the same room.
The need for an increased combination of modalities is echoed by Doug Ryan, business unit director for CT for Toshiba, the maker of the CT fluoroscopy equipment in use by Johns Hopkins. He cites this as an example of imaging that can be performed much more quickly and with lower radiation doses. “It brings in a big factor of patient comfort,” Ryan says. On the horizon, Ryan hopes to see three-dimensional applications and 256-channel detector systems, both of which are in research and development at Toshiba.
As with most imaging modalities, fluoroscopy continues to be driven by three factors: demographics, technology, and innovation. A population that is living longer than ever—and a baby boom that is soon to reach retirement age—may bring with it sicker patients and more complex cases. Although these patients may require more complex procedures, they also will require more time in the imaging suite. So for these procedures to remain cost-effective, they must be performed with great efficiency.
Improvements in technology, such as CT fluoroscopy, mean that many patients may be the beneficiaries of faster, safer, and more comfortable procedures. And thanks to physician, researcher, and vendor innovation, fluoroscopy will continue to expand its reach into new applications even as it sheds old uses. Fluoroscopy is a modality that will likely continue to reinvent itself.
