CT cardiovascular suite makes commercial debut at ACC meeting

Philips grooms new offering for CV mainstream

Philips Medical Systems is mounting a major effort to make CT part of the cardiovascular routine. The company showcased its CV Suite at the annual meeting of the American College of Cardiology March 30 to April 2.

The medical community has previously seen many of the technologies built into CV Suite. This ACC meeting, however, marked the debut of the Suite as a commercial product.

"The philosophy behind CV Suite is to provide cardiovascular CT that works on patients doctors see day to day," said Phil Prather, marketing director for Philips cardiovascular CT. "The goal is to be a tool, not a hindrance."

Earlier CV packages built for CT have required intensive work by technologists to obtain high-quality images. CV Suite is the exact opposite, he said, noting that image reconstruction is done on the fly and in the background.

"Users don't even see it," he said.

Different configurations of CV Suite, which is optimized for Philips' 16-slice Mx8000 IDT, offer a range of clinical capabilities. Each is more or less computing-intensive and more or less expensive. Budget-minded customers might select options with slower reconstruction speeds. Those who need productivity or intensive analysis may require faster speeds. RapidView, the postprocessing platform built into CV Suite, can be configured to generate from two to 20 images per second.

"CV Suite can serve the person who just wants to acquire and display cardiac retrospectively tagged data, or it can push the limits of technology with postprocessing applications such as organ perfusion and stent-grafts," Prather said.

The prices of these different configurations vary, and Philips sales staff have the final word.

High-end processing is supported by advanced software and proprietary ASIC chips developed by a Philips research lab in Germany. High-performance capabilities include qualitative and quantitative analysis tools that allow stenosis analysis, left ventricle/right ventricle analysis and function, stent planning, and virtual angioscopy.

Multicycle cardiac processing techniques combine data from several cardiac cycles, defined as the time from one R wave peak to the next. Philips electrocardiography monitoring equipment, hooked up to the patient, provides the timing data. ECG data are stored with the images, allowing retrospective review of the different cycles. Data are obtained in a single breath-hold that lasts about 15 seconds. Patients undergoing this procedure have trouble holding their breath for much longer.

In this period, 10 to 20 cardiac cycles may be captured. About 400 images are generated per cycle.

CV Suite adjusts CT data acquisition to varying heart rates, using a technique called beat-to-beat variable delay. This technique uses COBRA (cone-beam reconstruction algorithm) cardiac, which automatically determines the optimal number of cycles to achieve the best diagnostic results, then processes the data accordingly.

Equipped with CV Suite, the 16-slice Mx8000 can handle up to 115 beats per minute. This substantially diminishes the need to administer beta blockers to slow the heart.

In cardiac mode, the Mx8000 achieves a gantry rotational speed of 420 milliseconds. But Philips software is designed to segment the cardiac cycle to achieve temporal resolutions equivalent to 53 msec to 210 msec.

This segmentation technique is not unique. Past efforts to apply it, however, have met with mixed results. Typically, gantry speed and the number of slices generated per rotation were not adequate to sufficiently reduce or eliminate cardiac motion artifacts. Prather contends that the Mx8000, outfitted with CV Suite, can achieve that level of performance.

Physicians at Washington Hospital Center in Washington, DC, are counting on it. They will soon receive an Mx8000 outfitted with CV Suite. The unit will supplement conventional cardiac cath suites in which Washington Hospital staff conduct more than 10,000 diagnostic heart catheterizations per year, according to Prather.

In this program, the Philips Mx8000 is expected to provide a "first look" option for patients suspected of having cardiovascular disease. If that happens, the Washington Hospital experience may help clarify where CT fits in the grander scheme of cardiovascular imaging.