If industry claims are on the mark, clinicians can look forward to better images, more user-friendly software, and safer and more powerful injectors this year. In the contrast agent market, two companies came out with new formulations that each says will help users better distinguish normal tissue from diseased tissue. Another company is looking to expand the use of its contrast agent into the cardiac arena. In the injector market, safety and convenience are the focus, with prefilled syringes, features to reduce streak artifacts in heart studies, and longer battery life.
Improvements abound in this arena, and the imaging community will surely benefit?today and in the future. Here, company representatives and users discuss these enhancements and the future objectives for the medical-imaging field.
Bracco: Looking to Improve Images
Independent studies as well as those sponsored by the company indicate that a new contrast agent from Bracco Diagnostics Inc (Princeton, NJ) can help practitioners see damaged tissue in the central nervous system better than before, says Paolo Castelli, Bracco’s senior director of MRI marketing.
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| Bracco’s MultiHance injection was recently cleared by the FDA and is indicated for use in MRI of the central nervous system in adults to visualize lesions with abnormal blood brain barrier or abnormal vascularity of the brain, spine, and associated tissues. |
Bracco’s new MultiHance injection formula helps water molecules give off more energy during the relaxation phase of MRI and MR angiography (MRA) scans, Castelli says. Bracco recently received FDA clearance to market MultiHance for use in MRIs of the central nervous system.
During the relaxation phase, water in the body releases the energy it acquires from MR scanners. The burst of radiation generated during that energy release helps clinicians differentiate between lesions and surrounding tissue. MultiHance helps clarify the contrast between lesions and normal tissue, Castelli says.
Results of double-blind crossover studies of MultiHance recently were revealed,1 and another study was just completed in May. In addition, one Bracco customer is planning an evaluation of MultiHance involving about 1,000 patients, says VP of Marketing Bob Aromando.
“The MR community has not seen anything new for several years,” Aromando says. “It’s not a surprise that MDs wanted it.” Clinicians began using the product on its first day in inventory, he says. Institutions evaluating the product include the Mayo Clinic, the University of Pittsburgh Medical Center, Stanford University Medical Center, and Johns Hopkins Hospital and Health System.
Emil Cohen, MD, an assistant professor of radiology at Mt Sinai NYU Health (New York), has been using MultiHance since it came on the market early this year. “It’s giving us better images, as far as signal-to-noise ratio, than traditional contrasts,” he says. Cohen and his colleagues have gradually been increasing the amount of MultiHance that they use in MRA procedures and other applications. He says that thus far, they have not noticed any limitations or drawbacks.
E-Z-EM: New Contrast Formulation
E-Z-EM Inc (Westbury, NY) reported this past spring that its VoLumen contrast agent provides better distension of bowel walls than competing brands, based on the results of three studies presented at the Post-Graduate Abdominal Radiology Course in San Antonio this past March.
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| VoLumen (left), a low Houndsfield value oral contrast from E-Z-EM, provides improved distension and bowel wall visualization in MDCT and PET/CT imaging (right). |
This newly formulated oral contrast is a low-density barium sulfate suspension for use with multi-detector CT (MDCT) and PET/CT studies. Citing the results of the three aforementioned research studies, E-Z-EM claims that, compared to neutral and positive contrast agents used in MDCT scans of the abdomen, VoLumen gave better distension. Bowel distension is important to help clinicians determine whether disease conditions are present and to make an accurate diagnosis, says Roy Watson, product manager for VoLumen at E-Z-EM.
New York University physician Alec Megibow, MD, worked with E-Z-EM researchers to create VoLumen, which was originally used for CT angiography of the pancreas. According to Watson, Megibow now uses the product as his routine contrast agent and for CT scans of patients with Crohn’s disease.
Also, E-Z-EM will introduce a software program later this summer that the company says will enable administrators to monitor activities on multiple CT units both on- and off-site. The Empower injection system runs on a Microsoft Windows platform that already allows machines to talk to one another. In addition, E-Z-EM’s new Injector Reporting Information System (IRiS) enables scanners, injectors, and networks to share clinical information more easily, explains Phil Waldstein, E-Z-EM’s global product manager for injector systems.
Because IRiS runs on Windows, users can import clinical data from CT units to their office computers and put the information into a Windows database program, such as Excel or Access, Waldstein says. For example, technologists can digitally record multiple data points, including a time stamp and whether any extravasation occurs during injection. He says that IRiS focuses on managing the data gathered during CT scans rather than the scan itself. He adds, “All injector companies do the front end really well. This [aspect] differentiates us. We’re taking a back-office approach.”
The current version of IRiS?still in the testing phase?limits the number of possible data points to a preselected list, but that will change, he says. “The program will get bigger and better. Right now, the machine does all the inputs.” Future versions will allow users to choose and track multiple data points.
Still, with its limited information-tracking abilities, IRiS will help department heads control costs, Waldstein says, adding, “They’ll be able to see how much contrast was used and compare it to how much was bought.” Administrators also can use IRiS for quality assurance via the extravasation monitor.
GE Healthcare: Plastic Is Fantastic
GE Healthcare Bio-Sciences (Princeton, NJ) has released the results of a European study, published in February2 and funded by the company, showing that one of its contrast agents can guard against tissue damage while also cutting the cost of treating damage if it occurs.
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| To image the vasculature of the hand (above left), clinicians used GE Healthcare’s Visipaque?which, as with the company’s Omnipaque (above top right), is available in 50 mL polymer bottles, called the +PlusPak. GE Healthcare’s Omniscan is used to image the spine (above right). |
GE Healthcare says that its Visipaque contrast agent, a nonionic radiographic pharmaceutical with the same osmotic pressure as blood, reduces the relative risk of contrast-induced nephropathy. The company also says that Visipaque reduces the cost of treating some high-risk patients who have adverse reactions to contrast media versus the low-osmolar contrast agent iohexol.
Patients involved in the trial, known as the NEPHRIC study, had existing kidney problems and diabetes. Their condition put them at a higher risk of developing further kidney damage from contrast media. Physicians also assessed whether these 129 patients had cardiovascular disease.
Clinicians can deliver Visipaque using GE Healthcare’s recently redesigned plastic PlusPak bottle. The bottle’s benefits over its glass counterpart include a more compact design, less weight, and less chance of breaking. The PlusPak is easy to move and store, and it doesn’t contain any latex or DEHP, a compound with a risk of leaching into some chemical solutions used for intravenous treatments.
The PlusPak bottle also features a twist-off plastic cap, which replaces the metal crimp-on glass bottles. This feature reduces the risk of clinicians cutting themselves while filling a power-injector syringe or pouring contrast media into a sterile bowl.
Mallinckrodt: Convenience and Safety Top Feature List
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| Cleared by the FDA last December, the OptiVantage DH system from Mallinckrodt uses a saline flush following the injection of a contrast agent. |
In February, Mallinckrodt Inc (St Louis) brought a new dual-head injector to the market. Designed for injecting patients for CT scans, the new OptiVantage DH uses a saline flush following the injection of a contrast agent. The product received FDA clearance in December 2004. According to Product Manager Jim Knipfer, the system is set apart by both convenience and safety.
“We are the only injector manufacturer that supplies contrast media,” he explains. The OptiVantage package includes syringes with two sizes of premeasured contrast media. The system is designed for use with scanners that produce 16, 40, or 64 slices in every revolution of an X-ray tube.
The system also puts the instrument controls on the injection unit itself, rather than in a separate room. “The power head has a console built into it, so you can perform the programming at the bedside. [Clinicians] can stay there until it’s time to do the scan,” Knipfer says, adding that the most challenging aspect of putting the controls on the power head was adding more circuitry without making the unit bulkier.
With these controls, clinicians also can make OptiVantage work in sequence with CT scanners. With CT angiography in particular, being able to time injections and scans is critical. If a contrast-agent injection lasts 30 seconds, users can program OptiVantage to activate the scanner after 20 seconds, he says.
With regard to safety, premeasured syringes are just one of the system’s features. Clinicians still can use their own needles, but prefilled syringes minimize the risk of creating air bubbles. “Prefilling makes it easier,” he says. “And it reduces the chance of error.”
Technologists might also find it easier to test the strength of elderly patients’ veins with the OptiVantage, Knipfer says. The system enables techs to perform a patency check, in which a small amount of saline is pumped into a patient’s vein to see whether it is able to handle a full load of contrasting agent and saline chaser. If the vein is too fragile, extravasation occurs, pushing the test load of saline into the surrounding tissue instead of the vein. With a contrast agent, this effect could kill the tissue surrounding the vein, Knipfer says; saline solution will cause swelling, but it does no lasting damage. “No one makes a claim to prevent extravasation. The technologist has to do that. We just make it easier,” he says.
Also, OptiVantage can slow the rate at which fluids are delivered if, once a needle is actually in his or her arm, the patient moves during the injection.
Finally, if caregivers must load syringes themselves, the system can help users follow proper procedures. When technologists load a syringe, good clinical practice calls for them to purge air from the chamber and point the device upward. “The injector monitors those steps, and it won’t work unless they’re followed,” Knipfer says. When the injection procedure is complete, the unit displays results showing the target fluid volume and flow rate, compared to the actual rate and amount delivered.
While Mallinckrodt pushes for a wider berth in the injector market, the company faces a battle at least as tough in the contrast-agent arena. In March, Mallinckrodt had finished the second phase of tests showing that its OptiMark contrast agent can pick up lesions on heart tissue caused by heart attacks. The company now markets OptiMark for use with MRIs of the central nervous system.
Mallinckrodt expects to begin the third phase of testing for this new use of OptiMark in July, says Alicia Napoli, director of regulatory clinical affairs with the imaging division at Mallinckrodt. In this phase, investigators will begin working with a control group of patients who have not had heart attacks.
This month, the company expects to file for FDA clearance to begin marketing OptiMark as an imaging agent for heart lesions. The regulatory process generally takes 10?15 months.
Medrad: Power and Performance Improvements
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| Medrad’s Spectris Solaris EP (left) offers an integrated continuous battery charger option for high-volume MR scans, such as this brain MR (right). |
Medrad Inc (Indianola, Pa) has added some juice to its MR injectors with its Spectris Solaris EP (for “enhanced performance”), which debuted in March 2005 after receiving FDA clearance in December 2004. This third-generation MR injector provides increased performance, 3T compatibility, and more flexibility than before, while maintaining the features of previous injectors, says Associate Product Manager Bonnie Cowan.
The Solaris EP is designed for use with MR scanners up to and including 3T magnet field strength. It also allows the operator to perform more injections per single battery charge. “The number of injections will depend on the protocol used,” Cowan says, but users should see an increase in the number of procedures possible with one battery charge of between 75% and 100%.
To gain flexibility in power management, Medrad offers an option with the Solaris EP: the integrated continuous battery charging system (iCBC). The iCBC continuously powers the battery for uninterrupted injection during a single shift. The iCBC can be installed either inside or outside the scan room.
Radiologists at the David Geffen School of Medicine at the University of California?Los Angeles (UCLA) have been using the Solaris EP since early this year. “We’ve used it for an array of 3T MR imaging procedures and found it fully compatible and very reliable,” says Paul Finn, MD, a professor of radiological sciences at the school. “It runs on a significantly extended battery life [between charges] than our previous version.”
The Geffen School uses electronic power injectors for contrast studies that require accurate timing of injection rates, says Finn, who also is the chief of diagnostic cardiovascular imaging and director of MR research at UCLA. And that includes all MRA, he says.
Trials of the iCBC are under way, and so far, so good. The problems that the company anticipated, including artifacts and RF spikes, have not appeared thus far, says Glen Nyborg, senior MRI technologist at UCLA. The extended-life battery hasn’t hurt the image quality of contrast-enhanced MRAs, he adds. “The device on the whole is reliable and user-friendly.”
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| The Stellant CT injection system from Medrad now features the DualFlow enhancement. |
Medrad also has made a large investment in syringes to keep up with the demand for its Stellant CT injection system, according to Product Manager Tony Maiore. “We had an unbelievable year last year,” he says, adding that the market for CT products geared toward cardiac scans is exploding. ing.
In its latest tweak to the Stellant product line, Medrad rolled out the DualFlow feature, which targets this market. The dual-head Stellant D injector, which is capable of contrast and saline injection, solved the problem of visualizing the right coronary artery through the use of saline flush, the company says. Contrast media is injected into the patient and pushed into the right side of the heart with saline to achieve a dense concentration. However, before the DualFlow feature, the concentration of contrast in the left ventricle was less dense because it became diluted during transit through the lungs.
The problem of too much contrast density in the right side of the heart hampers visualization and can lead to diagnostic misinformation, according to Maiore. Until now, it has been difficult to reduce these distortions, known as streak artifacts or beam-hardening artifacts. “DualFlow provides a way to reduce these artifacts,” Maiore explains.
With the DualFlow feature, Stellant D users not only can visualize the right coronary artery but also can clearly see both the right side of the heart and the left ventricle, without artifacts, Maiore says.
Using a three-phase protocol that includes a second phase of contrast diluted with saline, the DualFlow feature enables clinicians to take into account the physiological dilution of contrast passing through the lungs and returning to the left ventricle. That leaves both sides more evenly diluted, Maiore says. “You get the same attenuation characteristics on both sides,” he says. Clinicians can vary the ratio of contrast and saline to suit their needs.
The DualFlow system is working out well so far for Larry Tanenbaum, MD, FACR, section chief for MRI, CT, and neuroradiology at Edison Imaging Group (Edison, NJ). “It’s just as reliable” for coronary CT scans as past models, Tanenbaum says. “Also, the DualFlow system lets us control the right-side heart density much better.”
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Clearly, the contrast agent and injector market is booming with options, and advancements are being made every day. As these developments are transferred to the user, patient care is, in turn, injected with power, safety, and convenience.
John Leonard is a contributing writer for Medical Imaging.
References
- Prokop M, Schneider G, Vanzulli A, et al. Contrast-enhanced MR angiography of the renal arteries: blinded multicenter crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine. Radiology. 2005;234:399?408.
- Aspelin P, Aubry P, Fransson SG, et al. Cost effectiveness of iodixanol in patients at high risk of contrast-induced nephropathy. Am Heart J. 2005;149(2);298?303.
