ATLANTA - An experimental 256-slice CT scanner can detail cardiac anatomy precisely enough to capture a coronary artery image in a single heartbeat, according to a presentation at the American College of Cardiology (ACC) meeting.
"The second spec 256-multislice CT seems to be a promising next generation CT for coronary and cardiac imaging," said Dr. Akira Kurata, Ph.D., a cardiologist in the department of radiology at Ehime University School of Medicine in Matsuyama, Japan.
"This device requires just one beat of the heart in order to develop a whole-heart image," Kurata wrote in his poster presentation.
The prototype scanner was developed by Toshiba Medical Systems of Tokyo. It uses Toshiba's Quantum detectors, with a matrix of 256 x 0.5-mm slices and 125 cm of organ coverage per rotation. At the 2005 RSNA meeting in Chicago, Toshiba estimated that the 256-slice scanner was two years from market.
Kurata reported on the image quality of the machine in three patients -- two patients who had previous myocardial infarctions and one with angina pectoris. The patients were treated with beta blockers and isosorbide dinitrate prior to an injection with 40-60 mL of contrast material at the rate of 3-4 mL/sec. The whole heart was scanned for 1.5 seconds to cover one cardiac cycle during breath-holding without electrocardiograph gating.
"The 256-slice CT demonstrated satisfactory assessment of the coronary arteries and left ventricular functional parameters without significant blurring," he said.
One of the main advantages of "one-beat whole-heart imaging" would be a reduction in radiation exposure, Kurata said. "The estimated effective radiation dose for one scan was 14.2 mSv in this study," Kurata said. "That is equivalent to the dose currently used for coronary CT angiography by multislice CT."
In addition, Kurata said the device could be used for volumetric cine imaging of the cardiovascular circulation. He said that even in patients with rhythm abnormalities, the device can complete the scan in one heartbeat.
By Edward Susman
AuntMinnie.com contributing writer
March 14, 2006
Related Reading
AuntMinnieTV: Advances in CT Technology -- Toshiba, January 19, 2006
Step-and-shoot acquisition cuts CTA dose, improves images, January 16, 2006
Toshiba highlights new x-ray, ultrasound systems, November 28, 2005
Motion-free heart images revealed with 256-slice CT, October 24, 2005
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