"Our hope was that 320 CTA would be faster than 64-slice CTA, which would allow us to decrease the dose of IV contrast we use," said lead investigator Dr. Jeff Jaskolka. "In addition, we hoped that doing the CT scan in a step-and-shoot fashion might ultimately reduce motion blur in calcifications and make heavily calcified vessels easier to interpret. Finally, the 320-slice CT is ideally suited to perfusion imaging, so we wanted a technique where the patient could potentially have a perfusion CT and CTA runoff in a single session."
Fifteen healthy male volunteers (mean age, 33 years) joined the prospective pilot study and were scanned with a 320-detector-row scanner (Aquilion One, Toshiba America Medical Systems, Tustin, CA). They were scanned from the diaphragm to the toes in a wide-volume step-and-shoot mode after IV injection of 80 mL of nonionic iso-osmolar iodinated contrast, 320 mgI/mL. Image quality was graded subjectively by two blinded readers, and objectively by calculating the signal-to-noise (S/N) and contrast-to-noise ratios (C/N).
In all, 93% of the scans were diagnostic, and average vessel S/N was 6.04 ± 3.05, with average C/N of 3.34 ± 1.88, they reported.
"We have shown that CTA on a 320-detector-row scanner is feasible at good image quality and with low doses of contrast," Jaskolka told AuntMinnie.com. "This opens the door for future research in the area including image quality optimization and combined protocols with runoff and perfusion."
