CT Angiography Shows Promise in Arterial Imaging

NEW YORK -- The introduction of three-dimensional multislice or multidetector helical ultrafast computed tomography angiography has dramatically improved the imaging of the aorta, according to a presentation at the Veith symposium on vascular medicine sponsored by Montefiore Medical Center.

The newer technique also allows perfect evaluation of smaller arterial vessels, said Dr. Jacques Busquet of the Clinique Chirurgicale du Val D'Or in Paris. He argued that these improvements in computed tomography angiography (CTA) can replace traditional angiography altogether.

"Over the past few years, an incredible improvement was made in terms of imaging, especially CTA," he said.

"That means with today's computers and medical imaging systems, we can reconstruct the image, so you can have slices at 2-3 millimeters. You have the ability to reconstruct the whole arterial system."

The advantages of CTA over angiography, are that it is faster, less invasive, and more accurate, Busquet pointed out. In addition, the high sensitivity for calcified plaques gives the exact anatomic characterization of the potential arterial stenosis, allowing an optimized interventional strategy (balloon diameter, type of stent [balloon-expandable or self-expanding], length, and risk of rupture).

"The other advantage of CTA over classical angiography is the ability to see the global structure of the artery because the arteriography looks just inside the lumen and only the lumen is shown," Dr. Busquet explained. "With CTA, the lumen is shown, but also the [arterial] wall and the structures, which could be very helpful during the surgery."

"The technologic improvements in CTA have made it the imaging modality of choice for many of the diseases we treat, especially aortic pathology," said Dr. Frank Pomposelli, clinical chief of the division of vascular surgery at Beth Israel Deaconess Medical Center, Boston.

"The ultrafast helical scanner has such good resolution that it may indeed replace arteriography in many circumstances. Nonetheless, it continues to have shortcomings, including the need for intravenous contrast, high levels of radiation exposure, and, in the past, limited ability to accurately determine the precise degree of stenosis in a narrowed segment," added Dr. Pomposelli. "In addition, unlike arteriography, there is no ability to immediately intervene at the time of imaging. For these reasons, I suspect that contrast arteriography will continue to be an important imaging and therapeutic tool in our treatment armamentarium."