MUSC Offers South's First Dual Source Scanner
“For a fast-moving organ, such as the heart, that obviously translates into much better diagnostic capabilities for heart disease,” says U. Joseph Schoepf, M.D., director of MUSC’s CT research and development. “It’s the best temporal resolution that we’ve ever had for structural imaging of the heart with a CT scanner.”
MUSC was among the first five hospitals in the country to launch this latest scanning technology developed by Siemens Medical. Like the 64-slice CT, the dual source CT captures x-rays from 64 perspectives in a single rotation around the patient. But with two tubes, the dual source CT can scan a patient’s entire chest with a breath hold of 10 seconds or less. This greatly reduces the occurrence of motion artifacts that can distort images and impede the diagnosis of coronary artery disease.
This new technology will help more patients avoid heart catheterization, Dr. Schoepf says. It is the ideal tool to assess patients who present with signs of coronary artery disease but are not at high risk of acute heart attack. The dual source CT can rule out other potential causes of chest pain in these patients.
This powerful device has other bonuses as well. The increased imaging speed means most patients will not need beta blockers to slow their heart rates, as with previous generations of CT scanners. Also, special filters on the scanner diffuse radiation away from the patient. That feature, plus the decreased exposure time, can reduce radiation by up to 75 percent compared to the 64-slice CT. The radiation exposure from the dual source CT is equivalent to the amount of natural radiation a person experiences in a year of living in the United States, according to Dr. Schoepf.
While the speed factor logically centers the dual source CT around cardiac imaging, Dr. Schoepf points out another exciting possibility. Each of the two tubes can be set to detect different energy spectra, so physicians will be able to distinguish various tissue types.
“For example, you can determine whether a person has too much iron in the liver,” Dr. Schoepf says. “Or you could edit out calcifications of the vessels, which would allow us to improve our diagnosis.”
To appreciate the significance of the dual source CT, it is important to understand the evolution of CT scanning, according to Dr. Schoepf, who has conducted thousands of CT scans since 1997 and is recognized as one of the top cardiovascular radiologists in the country. Any CT scanner, including this new one, can be used to scan any part of the body. But since the creation of the 16-slice CT scanner, advancements have focused on cardiac imaging – hence the push for speed. Among these more recent jumps in technology, the dual source CT is an engineering pole vault.
“We won’t see too many new technological developments in the next few years,” Dr. Schoepf says.