Correlation between US-PSV and MDCTA in the quantification of carotid artery stenosis

Stroke is a major cause of death and serious long-lasting neurological disability and the severity of carotid artery stenosis is one of the most important determinants of cerebrovascular events. The purpose of this paper is to evaluate the correlation between multi-detector-row CT angiography (MDCTA) and ultra-sound peak-systolic-velocity (US-PSV) in the quantification of carotid artery stenosis.

52 patients were retrospectively studied by using four-detector row CT and ultra-sound. Each patient was assessed for stenosis degree by using NASCET method when studied by using MDCT and by using PSV when studied by using US. Statistic analysis was performed to determine the entity of correlation (method of Pearson) between MDCTA and US-PSV. The Bland-Altman analysis was applied to assess the level of inter-technique agreement.

Sonographic PSV measurements ranged from 70 to 589cm/s. Distal ICA velocities ranged from 29 to 238cm/s. Linear regression analysis showed a good correlation (r(2)=0.613) between MDCTA-NASCET linear percentage stenosis and PSV and measured. PSV value that corresponded to a NASCET linear percentage stenosis of 70% was 283cm/s and with this values sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 75%, 88.6%, 90.7% and 70.5%, respectively.

Results of our study suggest that NASCET stenosis measured in MDCTA and PSV values have a good correlation. The use of a threshold of 283cm/s allows obtaining good value of sensitivity and specificity.