Cardiac Advanced Visualization: More than Just a Pretty Picture
When it comes to boosting radiologist productivity, the most obvious benefit to AV software is its utility in reviewing the thousands of images produced by a cardiac CT scan. “In terms of being able to read studies quickly, the software has become essential,” says John Rumberger, MD, PhD, director of cardiac imaging at the Princeton Longevity Center in Princeton, N.J. “In the old days, a CT scan had 20 to 50 images. Now we have hundreds, and in the case of cardiac CT, thousands of images to review. They simply cannot be reviewed properly without the advanced presentation tools.”
With CT angiography, efficient utilization of AV technology also can help maximize clinical workflow, particularly when it comes to issues of patient throughput, says Kavitha M. Chinnaiyan, MD, department of cardiology, Beaumont Hospital in Royal Oak, Mich. Chinnaiyan and her colleagues from Beaumont presented a study at the American Heart Association 2009 Scientific Sessions in Orlando in November in which they found that the use of coronary CT angiography in the emergency room can successfully triage at-risk chest-pain patients and does so faster—and cheaper—than standard diagnostic testing.
The study included 750 patients who had experienced chest pain in the 12 hours prior to admittance to the emergency department and had normal ECG and cardiac enzymes. The patients were randomized to either receive a standard diagnostic workup or CT angiography. There was no significant stenosis detected in 190 of the 262 patients who underwent the CT angiography, leading to their immediate discharge.
“Patients who came in with acute chest pain in the past would have to stay in the hospital for 24 hours or greater and undergo a whole bunch of tests before it was considered to be safe to discharge them,” says Chinnaiyan. “But now with CT angiography and the way in which we are able to visualize the coronary arteries, if they are normal, they [the patients] can go home within two or three hours. It says time and cost.”
In Chinnaiyan’s study, CT patients were discharged in approximately three hours compared with seven hours for those who received standard care. This resulted in a 38 percent reduction of costs, from the $3,500 for patients receiving standard care, to $2,000 for the patients who underwent CT angiography.
Personal preference & AVWhile most of the manufacturers that sell CT scanners also offer workstations unique to these products, Rumberger says that the software in those cases, “while good, is often cumbersome.” Thus, many facilities opt for advanced visualization software from independent vendors.
Beverly Jess, CT supervisor in the Metropolitan Heart & Vascular Institute at Mercy Hospital in Coon Rapids, Minn., says one of the driving forces behind the decision to install Vital Images’ Vitrea Enterprise Suite was dissatisfaction with the amount of time it was taking to do reads with the software that accompanied the facility’s CT scanner. “It was just taking a long time,” Jess says. “By using Vital Images, we were able to cut the reading time in half for the cardiologists.”
Jess just served as a beta tester for the Vitrea Enterprise Suite 5.1 upgrade and says she finds it to be “much more robust, particularly when it comes down to grabbing the smaller vessels—I don’t have to go in manually and do a whole lot.”
Rumberger has experience with all the major players in the third-party advanced visualization market and lauds their willingness “to adapt their software to the needs of their customers.” For example, he says, Ziosoft’s newer system allows the user to define certain controls that can differ from one user to the next, “which makes things a lot easier.”
Scott Flamm, MD, head of the section of cardiovascular imaging in the Cleveland Clinic Division of Radiology, says one size AV software doesn’t fit all personal and clinical needs, so he makes a range of AV software products available within his department.
“I’ve never been interested in trying to ram something down someone’s throat and saying, ‘this is what you use,’” Flamm says. “Allowing a variety of choices and having the best product ultimately win is what gets you the best buy-in from all of your people, and they feel better about the product they’re using.” It becomes a matter of personal preference, he says.
Within his department, TeraRecon is usually the choice for CT analysis, Flamm says, particularly with its thin client capabilities. “This is dramatically beneficial for us,” he says, “because it allows us to have the piece of software on just about any PC we have in our radiology area, the Heart and Vascular Institute area, and in our own area—the cardiac vascular imaging lab.”
The 3D viewThe use of 3D images is “a great tool to get the big picture—the overview of the vascular system or the cardiovascular structures,” says Flamm, adding that it lets him see the relationship of vessels to each other and to the soft tissue organs surrounding them.
“It allows you to manipulate in real time, to rate the objects so you can see them from multiple orientation and pick out some of the nuances, or subtleties of relationships between and among the different structures,” says Flamm.
But, Flamm also observes that with a 3D volumetric image, what is really being imaged is the external surface of a structure, “so there could be something inside that you wouldn’t necessarily see.
“For example, if I’m looking at a pulmonary artery in a 3D perspective and there’s a thrombus in the center of the vessel. I may not see it, simply because of the reconstruction method,” he says. “It’s possible to hide things inside of a cardiac or vascular chamber, so you’re not going to use a 3D volumetric reconstruction alone.”
It is, however, an excellent tool for demonstration purposes, says Flamm. “It’s particularly good to show to referring physicians—those who may not be as familiar with the transaxial images or understand the relationship of the structures to each other,” he says. “If you show someone the 3D image, they really get it and get it quickly.” Flamm adds that the same holds true when communicating with patients.
“We always put images in reports so that the referring doctor has something to refer to,” says Rumberger. “And of course, it helps the patient get a handle on what we are doing.”
The futureIn the future, Flamm says “everyone would like to see even greater automation—perhaps some fuzzy logic built-in auto-detection capabilities to make automated measurements and also be able to detect abnormalities automatically.”
And if the software is unable to detect them automatically, he notes, at least highlight them so that a cardiologist could “interact” with the software findings and determine what is normal, what is an artifact, and what is really an abnormality.
“I think the next big thing is going to actually be able to visualize the different aspects of coronary plaque without doing everything by hand,” says Chinnaiyan. “Kind of an automated plaque characterization system where we could get the plaque volume of the non-calcified plaque within a certain lesion and to be able to do it with a touch of a button. I know there are some systems out there already, but they do involve some level of manual work and some adjusting, so refining that and making it easier—that would be really cool.”