Intravascular ultrasound remains the reference standard for quantifying atherosclerosis. But its high cost and small risk of complications mean it can't be used as a screening test in asymptomatic people or in serial assessment of atherosclerosis, said Dr. Stella-Lida Papadopoulou and colleagues from Erasmus Medical Center. Noninvasive MDCT is much easier to administer, of course, but it has had variable success in measuring noncalcified atherosclerotic plaque.
The researchers examined 32 patients using both IVUS and 64-detector-row MDCT. They coregistered selected coronary arteries using a new image-fusion technique, and derived quantitative parameters from both imaging modalities.
Compared with IVUS, MDCT was 86% sensitive and 71% specific for the correct detection of more than 1,000 vessel-segment cross sections containing plaque, with sensitivity of 96% on a per-segment level, according to the authors.
"Our data demonstrated that the detection of atherosclerotic plaque based on MDCT-derived quantitative parameters in a similar fashion to IVUS was feasible," Papadopoulou told AuntMinnie.com.
Plaques located within the proximal and midvessel segments were detected with very high sensitivity, and most clinically relevant lesions are highly clustered within the proximal sections of the coronaries, she said. Moreover, the "very good diagnostic accuracy obtained at the segmental level is promising for the potential development of prediction models based on plaque presence on a per-segment basis," Papadopoulou noted.
Resolution at 64-detector-row CT remains too low for routine clinical use, though new imaging and reconstruction techniques are evolving rapidly to change the picture, she said.
