Imaging equipment is only half the solution for clinicians. The elements for a good study begin even before a patient climbs onto an examination table or slides into a scanner. Contrast media and the way it is injected into the patient can go a long way toward ensuring whether or not a scan yields a useful diagnostic image.
Since the early days of imaging, radiologists have used contrast agents. These drugs—like radiology itself—continue to evolve and improve. Today, many agents are less toxic and uncomfortable for the patient and easier to administer for the clinician.
Below is an overview of some of the tried and true, new, and/or improved contrast media and equipment that are keeping radiologists on the cutting edge of medicine.
Berlex: Safe ‘n’ Easy
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| Ultravist from Berlex is available in a variety of concentrations and is packaged in color-coded vials. |
Berlex Inc (Wayne, NJ) has several contrast media available to clinicians, including Magnevist, Ultravist, and Feridex IV.
One of the advantages of Magnevist is that it does not interfere with serum calcium measurements during laboratory testing. Also, it is available in 50-mL and 100-mL pharmacy bulk packages (PBPs) with 24-hour time of use and inventory-friendly 10 packs.
The PBPs allow multiple patient doses from a single vial, which simplifies weight-based dosing, minimizes contrast waste, and helps to decrease costs. But convenience and cost are only two of the things that have most impressed Mark Flyer, MD, director of body imaging at Maimonides Medical Center (Brooklyn, NY).
“I am very comfortable knowing that the agent has a superb safety profile,” he says. “Having used this agent for 12 years, I have never had a problem with it. In addition, the customer support is outstanding, and the educational programs provided by Berlex for radiologists, residents, technologists, and nurses are unparalleled.”
Next, Ultravist was introduced to the US market in 1995. It is a nonionic, iodinated, low-osmolar radiological contrast agent for intravascular administration. The low-viscosity agent allows for easy and rapid administration in all major IA and IV indications.
Ultravist is available in four concentrations—150 mgI/mL, 240 mgI/mL, 300 mgI/mL, and 370 mgI/mL. It also is available in a variety of vial sizes, including the 500-mL pharmacy bulk package for 300-mgI/mL and 370-mgI/mL concentrations. For additional safety, it is packaged in color-coded vials. Ultravist is not indicated for intrathecal use.
As with Magnevist, Flyer also is impressed by Ultravist’s good safety record. He adds that being able to receive Berlex’s contrast agents in prefilled syringes has helped his practice as well. “The prefilled syringe offers us great flexibility and ease of use for MR,” he says. “It is great for our technologists and helps improve throughput.”
In addition, Berlex also offers Feridex IV, an organ-specific MRI contrast agent used to detect and evaluate liver lesions associated with an alteration in the reticuloendothelial system.
Bracco: Plenty of Options
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| Isovue from Bracco has the highest iodine concentration of contrast approved for CT in the United States. |
Bracco Diagnostics (Princeton, NJ) has two MRI contrast agents, ProHance and MultiHance. Introduced to the United States in 1992, ProHance is available to image the central nervous system (CNS) with a high dose indication in adults (0.1 plus 0.2 mmol/kg cumulative dose). It has high stability and low osmolality.
ProHance is indicated for use in MRI in adults and children older than 2 years to visualize lesions with abnormal vascularity in the brain, spine, and associated tissues. ProHance also is indicated for use in MRI in adults to visualize lesions in the head and neck.
Next, Bracco launched MultiHance in the United States in 2004. MultiHance is an MRI contrast agent that has a marked increase in signal-to-noise ratio (SNR) in T1-weighted images. Even though it has been available only for a short period of time, MultiHance has proven its effectiveness in clinical studies.
“It has twice the T1 relaxivity compared with [other approved] gadobenate dimeglumine contrast agents,” says Kenneth R. Maravilla, MD, professor of radiology and neurological surgery at the University of Washington School of Medicine (Seattle). “This results in a significantly greater contrast-enhancement effect for the same dose compared with the other agents.
“In addition, MultiHance also has a T1-enhancement effect on the liver so that it can be used for liver-enhancement studies as well in order to generate a hepatogram effect on delayed imaging,” Maravilla continues. “So it behaves like a standard agent when scanning is performed shortly after injection, but it shows liver enhancement related to functioning hepatocytes on delayed scans. Our body imagers find this useful, although it is an off-label use of MultiHance, since it is not FDA approved for this indication.”
MultiHance is indicated for intravenous use in MRI of the CNS in adults to visualize lesions with abnormal blood brain barrier or abnormal vascularity of the brain, spine, and associated tissues.
MultiHance is about 20% higher in price than other similar contrast agents, but Larry Tannenbaum, MD, section chief MRI, CT, and neuroradiology at the Edison Radiology Group (Edison, NJ), finds that it is worth the added cost. “It has double the effectiveness, [so it’s worth paying a little more for it],” he says.
In addition, Maravilla says that he looks at safety of the product, and, as with Tannenbaum, he applauds the effectiveness of MultiHance. “[Up until now,] decisions as to which agent to use have pretty much been related to cost and to name recognition,” Maravilla explains.
On the CT side, Bracco offers Isovue, a nonionic contrast medium that has been on the US market for 20 years. It is indicated for a variety of radiological procedures and comes in an assortment of iodine concentrations and packaging options. Isovue also comes in multi-pack PBP of 200-mL and 500-mL volumes.
Isovue-370 has the highest iodine concentration of contrast approved for CT in the United States. Isovue-M is indicated for myleography. The high iodine concentration is the primary reason that Tannenbaum uses it in his practice. “It is incredibly fast and offers the highest contrast,” he adds.
E-Z-EM: Easy Does It
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| The EmpowerCTA system from E-Z-EM provides double-barrel injector capabilities. |
The family of CT injector systems from E-Z-EM Inc (Lake Success, NY) includes the Empower CT (single barrel) and EmpowerCTA (double barrel). The company’s CTA system was designed for CT procedures that need a saline chase; the system can detect extravasations as well as capture and retrieve injection data. EmpowerCTA includes the injector head, injector controller, extravasation-detection accessory and mounting option, remote control, and power supply.
Dennis Foley, MD, a professor of radiology and director of digital imaging at the Medical College of Wisconsin (Milwaukee), has found the EmpowerCTA to be useful for both cardiac and noncardiac CT angiography. “The contrast injection for cardiac CT is performed with a dual-injection rate through the contrast-media syringe, followed by a saline flush from the second syringe to shape the contrast bolus,” he explains. “This provides optimum opacification of the left side of the heart and coronary arteries while minimizing opacification of the right side of the heart. This avoids artifacts from retained contrast medium in the right side of the heart obscuring segments of the right coronary artery.”
The extravasation-detection accessory uses the principle of bio-impedance to locally monitor the patient’s tissue over the outlet of the venous-access catheter. If the contrast should start to extravasate, the tissue bio-impedance underneath the EDA patch changes. If this occurs, the contrast injection is paused, and the technologist is informed via a system voice prompt.
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| The data regarding the procedure is collected on the IRiSCT software system. |
Data regarding the procedure is collected and reported by the company’s CT Injector Reporting Information System (IRiSCT). This software package, which was released in December 2005, is built into the Empower systems and allows for easy analysis of injection information, including CT contrast utilization, injection, and extravasation data.
According to E-Z-EM product manager Phil Waldstein, IRiSCT serves three different needs: business, clinical, and quality. From a business perspective, the IRiSCT allows a true monitoring of the contrast use. “[Typically,] an administrator knows how much contrast he has bought, but not how much of that has been used,” Waldstein explains.
The system also reports trends in use and can help identify workflow bottlenecks, allowing the imaging department to become more efficient and productive.
From a clinical perspective, Waldstein says, the IRiSCT helps radiologists develop procedures that will deliver contrast to the targeted areas when it is needed—something that is particularly crucial with faster, multi-slice CT scanners. Once the procedures are developed, the IRiSCT helps to maintain protocol compliance.
The IRiSCT also can be used in quality meetings, since it records all data for every patient. Waldstein gives the example of the patient who occludes the line when the contrast is being delivered, building up pressure, which the machine negates by slowing the amount of contrast. The result is a poor image, but one that can be explained by the objective data provided by the IRiSCT.
All of the data, no matter the use (clinical, administrative, or quality control), is available to administrators and clinicians via their desktops. The computers can receive the data directly from the injection system through the IRiSCT, which is able to operate using standard desktop programs. The data can be used to generate reports in any form that is beneficial to the user.
Although the product is new, Waldstein says that it is a hit already. “We’re getting a lot of great feedback,” he says. E-Z-EM is looking at making some improvements to the IRiSCT in its next iteration, including allowing key patient data to be included in the patient record.
GE Healthcare: New Look
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| GE Healthcare’s Omnipaque is available in the safe and user-friendly PlusPack plastic packaging. |
Omnipaque from GE Healthcare Bio-Sciences (Princeton, NJ) is a contrast agent used for X-ray in a range of indications, including intravascular diagnostic procedures—such as coronary angiography, spinal-cord imaging, and body-cavity procedures. The product is a low-osmolar, nonionic, iodinated contrast agent. It is approved for use in adults and children, and it is available in a range of packaging options.
Visipaque is an X-ray contrast medium for use in adults for cardioangiography, cerebral angiography, peripheral arteriography, abdominal angiography, urography, venography, CT enhancement, upper gastrointestinal tract imaging, arthrography, hysterosalpingography, and endoscopic retrograde cholangiopancreatography. It also can be used for lumbar, thoracic, and cervical myelography in adults.
Elliot Fishman, MD, professor of radiology and oncology at Johns Hopkins Hospital (Baltimore), uses both Omnipaque and Visipaque for coronary procedures. “Omnipaque and Visipaque both have a good safety profile and good results,” he says. He uses Visipaque on his older and sicker patients, because it is a low isomolar agent.
The company also has made other improvements that he finds beneficial. “The packaging is better,” Fishman says. “It has changed from glass to plastic.” The plastic packaging is made from polypropylene and is, according to the company, virtually unbreakable. An additional advantage over glass is that the plastic packaging is more compact and lighter than its glass sibling. GE Healthcare introduced the plastic packing, known as the PlusPack, in 2003.
Guerbet: Simplifying Things
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| This CT angiogram of the abdominal aorta was imaged using Guerbet’s Oxilan agent. |
Oxilan is a nonionic contrast medium available from Guerbet LLC (Bloomington, Ind). Its molecular structure includes a hydrophobic region to promote molecular aggregation, reducing the osmolality. The molecular design also features a terminal hydrophilic group, which results in reduced risk of side effects from binding with biological structures. The hydrophilic group also increases the solubility of the molecule.
Oxilan is indicated intravenously for contrast-enhanced CT head and body imaging and excretory urography. It is indicated intra-arterially for cerebral arteriography, coronary arteriography/left ventriculography, aortography, selective visceral angiography, and peripheral arteriography.
John A. Osborne, MD, PhD, FACC, adjunct assistant clinical professor at the University of Texas at Arlington and director of noninvasive (CT) angiography at CSANT Cardiology (Grapevine, Tex), uses Oxilan for several reasons. “It has a high iodine content per milliliter, is nonionic, and is nearly iso-osmolar. It also has a low viscosity to facilitate ease of use. And it is cost effective,” he says.
Oxilan has benefited Osborne in several ways. “Using more Oxilan has allowed us to simplify our stocking needs,” he says. “We no longer need to stock expensive iso-osmolar and low-osmolar agents, and it has simplified our contrast protocols for patients at risk for contrast-induced nephropathy and/or those who have a history of contrast reactions/allergies.”
Mallinckrodt: Optimal Options
Mallinckrodt (Hazelwood, Mo), a division of Tyco Healthcare, offers the OptiMark (gadoversetamide injection) and Optiray (ioversol injection) family of contrast agents. OptiMark is a gadolinium-based, IV contrast media for MR imaging of the brain, spine, and liver. This nonionic and low-osmolar agent is available in both single-dose and multi-dose packaging, and it is approved for power injection.
The Optiray line (not for intrathecal use) includes Optiray 160, 240, 300, 320, and 350 concentrations. All of the products are injectable, low-osmolar, nonionic contrast media. Optiray 160 is used to visualize arteries using digital subtraction techniques. Optiray 240, 300, 320, and 350 are used in organ-tissue enhancement in CT, X-ray, and fluoroscopy procedures. Optiray 240 is indicated for cerebral arteriography, venography, excretory urography, and CT of the head and body. Optiray 300 is indicated for cerebral arteriography, peripheral arteriography, venography, excretory urography, and CT of the head and body.
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| Mallinckrodt’s OptiVantage DH features an LCD powerhead that is fully programmable at the remote console, allowing technologists to change protocols, perform saline injections, and fill syringes with the touch of a button. |
Optiray 320 is indicated in adults for angiography throughout the cardiovascular system. It also is indicated for pediatric angiocardiography, pediatric CT of the head and body, and pediatric excretory urography. Safety for use with newborns has not been established.
Optiray 350 is indicated for peripheral and coronary arteriography, left ventriculography, venography, intravenous excretory urography, IV DSA, CT of the head and body, angiocardiography, and pediatric angiocardiography (not including newborns).
On the injector side, Mallinckrodt offers the OptiVantage DH, CT9000ADV, and OptiStat handheld for CT; the OptiStar LE for MRI; and the Angiomat Illumena for angiography. The company has made a number of improvements to its various injector systems over the past few years. For CT, Mallinckrodt introduced the OptiVantage DH and the CT9000ADV/OptiStat combination, both of which provide dual-head injection platforms. In addition, with the OptiVantage DH, the company has a planned pipeline of software enhancements. Also for CT, Mallinckrodt offers the injection bolus shaping technology, OptiBolus. With Ultraject prefilled contrast syringes for both Optiray and OptiMark and the complete line of injectors, Mallinckrodt offers the only fully integrated contrast delivery system.
The company’s MRI-injection platform is a battery-free, nonferrous, 3T-compatible system. As with its CT offerings, Mallinckrodt has a planned pipeline of software enhancements to address “voice-of-customer” input. In addition, the company also introduced a mobile mount for the OptiStar LE.
The Angiomat Illumena system is easily configurable to fit the user’s needs. It provides dual functionality for angiography and CT. And like Mallinckrodt’s other injector systems, it has a planned pipeline of product enhancements.
According to Jim Knipfer, senior product manager for LF power injectors at Mallinckrodt, the company’s injection systems “provide a full range of injection parameters, flow rate, volume, and pressure that exceed what is demanded by current clinical procedures.” Many of these parameters are achieved, Knipfer adds, by simply addressing the needs of the customers.
When considering which injection system to purchase, radiology departments need to evaluate several factors. Knipfer advises, “A variety of parameters drive the final decision on which injection platform will be purchased, [including] contractual obligations if the member is in a group purchasing organization; clinical performance relative to medical needs; ease of use; the ability to maximize patient throughput, safety, and reliability; and the overall economics, such as system cost, use cost, and throughput.”
MEDRAD: Quite Stellar
MEDRAD Inc (Indianola, Pa), introduced its first CT injector in the 1980s. Today, its Stellant CT Injection System is both easy to use and upgradeable. Two models compose the Stellant CT family: the Stellant Sx, a single-syringe, contrast-only injector; and the Stellant D, a dual-syringe injector for performing cardiac CT, cardiac CT angiography, and other advanced procedures. It allows saline injection before and after contrast in a diagnostic protocol for saline test injections, saline timing boluses, and saline flush. The dual-flow feature also enables simultaneous injection of saline and contrast.
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| This cardiac CT image was achieved with MEDRAD’s Stellant D with DualFlow for simultaneous injection, which controls the contrast to allow for visualization of both sides of the heart and coronary artery with reduced streak artifacts. |
Radiologists who use the Stellant D system sing its praises. David Dowe, MD, COO of Atlantic Medical Imaging (Galloway, NJ), commends both the reliability and flexibility of the Stellant’s flow rate. “It allows me to do anything I want, [such as] giving me a higher flow rate for obese patients,” he says. “It’s a workhorse.”
Dowe adds that the ability to use the dual-flow injector also helps to save time. This is particularly useful when imaging obese patients—Dowe’s specialty is cardiovascular imaging—who benefit from a faster flow rate. He also uses an isomolar contrast agent, which is less traumatic for both normal-size and obese patients.
For Joan Lacomis, MD, of the University of Pittsburgh Medical Center (UPMC), the Stellant D has other advantages as well. “We can tailor the bolus to our areas of interest,” she says. “It’s very responsive to our needs. The injector is easy to use and is reliable.”
Even though it is reliable and easy to use, MEDRAD is continuing to build on the Stellant D system. Its newest enhancements include open-source interface capability with the Sensation and Emotion CT scanners from Siemens Medical Solutions (Malvern, Pa) using the iFlow interface device (which ensures proper timing of the scan and the injection). Another feature of the Stellant D is SmartFlow patient-based dosing software (which is geared specifically for cardiac imaging). Also, DualFlow is an option on the Stellant D that provides simultaneous injection of contrast and saline, helping clinicians control the amount of contrast enhancement on both sides of the heart and the right coronary artery. The user could employ iFlow, SmartFlow, and DualFlow in a single procedure, as they are all complementary.
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| This MR image of the vasculature of the Circle of Willis was achieved with contrast provided by MEDRAD’s Spectris Solaris EP injection system. |
For J. Paul Finn, MD, chief of diagnostic cardiovascular imaging and director of the MR research department at the University of California, Los Angeles, MEDRAD’s Spectris Solaris EP MR Injection System is his injector of choice. “For injectors, price is important, but performance is crucial,” he says. “For our work with MRA, we sometimes inject small volumes and sometimes use fast injection rates.”
According to the company, the new EP product line builds on the original’s flexibility and ease of use. It also has enhanced flexibility in terms of power management—the integrated continuous battery charger allows clinicians to use either battery power or alternating current wall power. The Spectris Solaris also has 3T compatibility for MRA applications.
Future Hopes and Dreams
As the past has shown, contrast agents and injectors will continue to change and improve. And clinicians have needs and wants that they hope manufacturers and researchers will soon fulfill.
UPMC’s Lacomis hopes that in the future, contrast media will continue to decrease in dose and toxicity to the patient. As for injectors, she hopes they will continue to be easy to use and have a high reliability factor.
SURF’S UP! |
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For more information about the companies and products discussed in this feature, be sure to visit the following links: Berlex–www.berlex.com |
Johns Hopkins’ Fishman hopes for other improvements. “I’d like to see agents that are more organ specific,” he says.
The Medical College’s Foley hopes to see more integration of his various tools in the future. “We anticipate further integration of the injector with the CT scanner to match the injection and acquisition more precisely,” he says.
One thing is for certain in terms of contrast media and injectors: They are in the midst of an ongoing evolution that is giving radiologists and interventional cardiologists more options and more diagnostic power.
C. A. Wolski is a contributing writer for Medical Imaging.
