Multi-Modality Workflow for Improved Stent Placement and Patient Outcomes

John D. Carroll, MD
John D. Carroll, MD
Introduction Historically, cardiologists and other heart health specialists have employed cardiovascular X-ray in the cath lab to help diagnose blockages and place stents. Two new innovations the use of CT and X-ray together, and the addition of 3D visualization capabilities to cardiovascular X-ray have the potential to increase clinical confidence. Specifically, using the Philips Brilliance CT scanner in combination with the Allura Xper FD20 C/V X-ray system with Allura 3D-CA (3D Coronary Angiography) can enhance both diagnostic workflow and interventional success for stent placement. Using different imaging modalities together is nothing new; clinicians often order follow-up CT for X-ray studies, MRI after ultrasound, and so forth. What’s new is the use of the two in tandem. Images captured in one modality can actually send positioning coordinates to another; clinicians can view images from one diagnostic modality while viewing images from another during the interventional procedure. At each step, the images and associated data can be transferred as the clinician requires, mapping to their desired workflow. The Brilliance CT, a 64-channel CT, enables coronary artery imaging that boosts clinical capabilities. Its scanner produces split-second, high-quality 3D images, permitting clinicians to see more anatomical detail in a fraction of the time needed with some older CT systems, potentially improving patient comfort. Through its automated DoseWise radiation protocols, the amount of radiation used can be reduced without sacrificing image readability. The quality of image also can reduce the amount of contrast agent needed. The Allura Xper FD20 with Allura 3D-CA offers accurate 3D modeling of the coronary arteries. This cardiovascular X-ray system improves image quality and X-ray efficiency, with a 4 times greater resolution than other systems on the market. Why 3D? Often, 2D imaging misrepresents lesion lengths and overlapping branches in bifurcations. A recent study showed that 14 percent of stenting cases had foreshortened views due to 2D misrepresentation. The Allura Xper FD20 with Allura 3D-CA is a new technology that is being launched by Philips in 2005. Like the Brilliance, the Allura FD family uses technology to reduce patient and staff radiation exposure. For example, an accurate 3D model can be created by selecting the two most appropriate images from the 120 images acquired during a four-second rotational scan, reducing both contrast usage and dose. The combination of CT and X-ray increases the amount of clinical information available to help boost clinical confidence for example, the same artery can be viewed from several different angles, or smaller arteries can be examined to see if the CT gives a better view in one modality versus another. A Case Study To understand the benefits of multi-modality imaging, it may be instructive to discuss a hypothetical case made up of a composite of experiences at the University of Colorado Hospital where we have been partnering with Philips to develop 3D coronary modeling. Let’s take, for example, a female patient who presented with cardiac pain upon exertion. Her ECG and stress test were normal. Our team used Brilliance CT images to diagnose a significant lesion in the left main artery and soft plaque. The CT’s rate responsive image acquisition technology adapts to sinus rhythm and acquires heart data without the use of beta-blockers. The patient needed to hold her breath for only 6 seconds, and the entire scan took less than 10 minutes. Using built-in image processing and cardiac analysis software, we extracted the cardiac structure and arteries and took a stenosis measurement. The cross sectional view in the Brilliance workspace enabled us to rotate the vessel tree to get exact coordinates to send to the Allura Xper FD20 system. We then used the Allura Xper FD20 system for both intervention planning and the actual procedure. Using the 3D-CA analysis function, we determined the true length and complexity of the lesion and determined the C-arm coordinates, without needing to perform either manual or catheter calibration. From there, we used the Allura Xper FD20 system to determine the appropriate stent size and position. During the actual procedure, we also used a feature on the Allura Xper FD20 system called StentBoost to check for proper stent deployment. The results? Using the Allura Xper FD20 and Brilliance system together, both contrast agent usage and radiation dosage were reduced by 30 percent comapred with other workflows. The two imaging modalities integrated automatically, and our clinical team increased their confidence in terms of diagnosis, treatment plan, positioning of the patient and C-arm, as well as stent deployment. Conclusion Through innovations in cardiology workflow and imaging technology, clinical cardiologists can positively impact productivity and confidence, from diagnosi through intervention and follow-up. Through such collaborations as those of our hospital and Philips, cardiologists can achieve their key goals: the dual outcomes of positive patient outcomes and advanced levels of operational efficiency. Readers interested in learning more about multi-modality workflow for improving stent placement can come visit the Philips booth at the 17th Annual Transcatheter Cardiovascular Therapeutics (TCT) meeting on October 17, 2005, in Washington, D.C. at the Washington Convention Center’s Main Arena. For additional information, contact Philips at 1-800-229-6417 or visit www.tct2005.com.