Angiography No Longer Limited to Cardiology
As catheter-based, minimally invasive procedures expand rapidly beyond treatment of the coronary arteries into all areas of the human anatomy, angiography X-ray imaging systems have moved beyond their original purpose of simple vascular imaging. Today, in addition to interventional cardiology, cath labs are frequently shared by numerous specialists, including interventional radiology, interventional oncology, electrophysiology (EP), vascular surgeons and neurology.
“The days of dedicated labs are gone,” said Reaz Rasul, general manager, GE Interventional Systems. “You are going to have all kinds of surgeons and other specialties coming in and using these labs more and more.”
For this reason, GE and other vendors are now tailoring technology packages for each user, depending on what their labs are used for. These include specific technologies for EP, interventional radiology, vascular surgery, cardiology and neurology. This change in the market led GE this past fall to use a new concept name for its angiography systems, now called Innova Image Guided Systems (IGS). It introduced the IGS name during the 2011 Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium.
According to the market research firm IMV Medical Information Division’s December 2011 report on angiography system market trends, there were about 1,710 cath labs in the United States, which performed an estimated 4.9 million procedures in 2010. At least 50 percent of the total cath lab volume consists of noncoronary angiography procedures, IMV found. In addition to interventional cardiologists and radiologists using the angio suite, IMV found vascular surgeons are the second most likely physician type to be using cath labs, performing procedures in more than 60 percent of the cath lab sites.
“While the total angio lab procedure volume has been relatively stable, the procedure mix has broadened,” observed Lorna Young, senior director, market research. “From 2004 to 2010, the number of peripherally inserted central catheter line/vascular access, vertebroplasty, sacroplasty, kyphoplasty, biopsy, radiofrequency (RF) tumor ablation, and other RF studies has contributed to the overall volume of procedures performed in angio labs.”
IMV report found 52 percent of cath labs have one room, 31 percent have two and 17 percent have three or more rooms. About three-quarters of planned purchases are for replacement units, and one-quarter will be additional units.
Rasul said other trends he is seeing in the market include increased concern about cost. As a reflection of the poor economy and its impact on healthcare providers, a big theme across the show floor at RSNA 2011 was an increased focus on more economical systems.
All vendors say the complexity of interventional procedures has increased, raising interest in more advanced visualization and 3-D guidance tools. More complexity also means longer imaging times, so users are more concerned about monitoring dose.
Increased EP Usage
GE Healthcare has seen a lot of growth in electrophysiology (EP) technology adoption to convert cath labs into full EP treatment facilities, said Dave Tolan, marketing manager at GE. “The technology is really making these complex procedures more available.”
In January, GE announced a long-term agreement with Biosense Webster Inc. to co-distribute their EP systems and collaborate to enhance functional integration. GE also released the IGS 620 and 630 dedicated EP biplane angiography systems. Both offer default dose protocols optimized for EP procedures. EPVision applications also offer advanced 2-D and 3-D applications to help EPs visualize anatomy and devices.
In 2011, Philips reported its 100th install of interventional EP angiography system with EP cockpit XL. The control room is more streamlined, with options such as keyboard and video switching, and Philips’ EP navigator offers a comprehensive view of where a device is in the heart.
New Software Tools
• Siemens Healthcare’s syngo Neuro PBV IR (parenchymal blood volume interventional radiology) provides visual assistance in the diagnosis and treatment of vessel malformations. In neuroradiology, this feature assists physicians in the treatment of stroke patients by displaying a color-coded qualitative map of cerebral tissue. Parenchymal blood volume information is acquired with two C-arm rotations and a steady contrast injection. The information is available in less than 40 seconds.
• GE’s AngioViz yields additional information from digital subtraction angiography (DSA), utilizing a technique called parametric imaging. It examines each pixel and determines the peak opacification caused by the contrast, and the time it takes for that pixel to reach that peak. These two parameters can be displayed separately, or in a combined color-coded image.
• Toshiba introduced Volume Navigation 3-D roadmapping for the Infinix-i product line, allowing real-time procedural guidance. It links the movements of system components with the fusion 3-D and fluoroscopic display, so despite changes in table and C-arm position, the 3-D overlay is automatically aligned.
• GE began offering Veran’s ig4 fusion imaging angiography electromagnetic navigation system using 4-D registration to precisely target cancerous lesions. The multimodality system helps deliver instruments to small targets in difficult to access regions of the human body.
• Several vendors introduced navigation for structural heart devices. These tools offer real-time, 2-D X-ray images and 3-D models from multiple modalities and synchronize images with ECG gating to compensate for heart and respiratory motion.
The Next Generation
At RSNA 2011, GE unveiled the Discovery IGS 730, the first angio system designed to capture the advantages of both fixed and mobile C-arm systems. It uses a wheeled, wireless, motorized gantry to move anywhere in a room. However, it uses precise laser-guidance for so the system knows the exact location of the gantry to produced predictable and precise trajectories. The system offers all the advantages of a fixed system, with a wide bore C-arm, 3-D acquisitions and more than 20 advanced visualization applications. The mobility of the system also enables complete patient access without obstructions. GE envisions the system as a hybrid OR solution. The system is pending regulatory clearance in both Europe and the United States.
Concern Over Dose
In 2011, the Society for Cardiovascular Angiography and Interventions (SCAI) published guiding principles and best practices for the development of radiation safety programs in cardiac cath labs. It focused on the need for safe practice and continuing education for all facilities that perform angiographic interventions. This first-of-its-kind document offers a summary of program development criteria, including procedural guidelines, training, dose management and monitoring, equipment considerations and potential safety concerns.
In 2011, Toshiba introduced a DICOM radiation dose structured report on all new Infinix-i systems to automatically record dose information from every X-ray event. The data is transferred into a standard format suitable for storage, making it easier to document, manage and evaluate overall dose usage.
For more information of systems on the U.S. market, click on the comparisons chart tab at the top of the page.
1. “2011 Interventional Angiography Lab Market Summary Repor.” IMV Medical Information Division. December 2011. www.imvinfo.com
2. Charles E. Chambers, et al. “Radiation Safety Program for the Cardiac Catheterization Laboratory.” Catheterization and Cardiovascular Interventions (CCI), January 2011, vol. 77, issue 4, pages 546-556. http://onlinelibrary.wiley.com/doi/10.1002/ccd.22867/pdf.
- GE Healthcare offers software for its angiography systems to enhance visualization of implantable devices, as seen here with an aortic stent graft.