Digital imaging success spills over into angiography

Digital technology is moving into x-ray-based subspecialties in ways that not only deliver better images but also offer views not typically achieved by those modalities. These new capabilities invigorated vendors on the RSNA exhibit floor.

Siemens barely had FDA clearance in hand before it unveiled DynaCT, an enhancement for C-arm angiography systems. Available as an enhancement to the Axiom Artis dFA, dTA, and dBA systems, DynaCT enables clinicians to perform CTA in the angio suite, obtaining images similar to those delivered by dedicated gantry-based CT units.

Tissue differentiation is around 10 HU, facilitating visualization of such soft-tissue abnormalities as abdominal tumors and cerebral hemorrhage.

The new product eliminates the need to transfer patients from the angio suite to another modality for follow-up procedures that require soft-tissue inspection. This convenience has not been available before, according to Gerhard Schmiedel, head of radiography solutions for Siemens. The company expects the system to have its greatest impact on patients suspected of stroke, as time is often a critical factor in their diagnosis and treatment.

The technology will also benefit patients undergoing interventional procedures. Physicians will be able to obtain CT-like images without the need for an additional machine in the interventional suite.

"Physicians will be able to do direct follow-up in the angio suite," Schmiedel said. "The other advantage is the capability of doing DynaCT-guided punctures or RF ablations for tumors."

Data are acquired with a 10-second C-arm spin. A volumetric image is then reconstructed on Siemens' Leonardo workstation.

In more mainstream cardiovascular imaging, Philips Medical Systems showcased its Allura Xper FD20, a flat-panel detector system designed for general neuro and cardiovascular applications. Exhibited in 2003 as a work-in-progress, the system, now commercially available, provides images that have about four times the resolution of those captured on conventional angiography systems, according to Philips.

"We've imported our Xres image processing technology from MR and ultrasound, which gives real-time image improvement," said Richard R. Fabian, business unit director for cardiovascular x-ray at Philips. "The detector and algorithms have helped give us the best images possible."

The system also features a capability called fluoro loop, which allows the user to review the last 10 or 20 seconds of fluoroscopy.

GE Healthcare rounded out the major vascular offerings with its Interventional Suite, featuring the OEC 9800 MD digital motorized mobile imaging system. The suite enables carotid artery stenting, renal angioplasty and stenting, coronary diagnostics, and coronary angioplasty and stenting.

"This is the only motor-driven mobile C-arm on the market today," said Kristi D. Saathoff, downstream marketing manager for GE. "We think it's a big deal because it gives physicians more control over the movement of the C-arm, meaning quicker scanning and better accuracy. It also has increased heat management capabilities - we have no problem operating the C-arm for continuous back-to-back procedures without overheating it."

GE also introduced enhancements to its Innova 3100 and 4100 cardiovascular and interventional systems. The flat-panel detector products now excel at visualizing fine vessels in the peripheral vasculature, helping physicians assess vascular disease and precisely place interventional devices such as stents and balloons. The advance is due to a new automated imaging technique called InnovaBreeze, which manages data acquisition from the stomach down through the legs to the feet.

Using this new capability, the patient table moves to follow the injection of contrast medium from the aorta in the abdomen through the peripheral vasculature. InnovaBreeze automatically combines the stream of images acquired along the way into a single image of the contrast-filled blood vessels.

Adding a new perspective to angiography, Toshiba America Medical Systems upgraded its Infinix VC-I vascular/angio system with 3D angio. The system comes standard with an image intensifier, but the company noted that a flat-panel detector is in the works. Another work-in-progress, Cerebral Vessel Fly Through, will postprocess vessels smaller than 1 mm.