Carotid bifurcation CT angiography: assessment of interactive volume rendering.
ABSTRACT The purpose of this study was to compare the accuracy of CT angiography (CTA) for the assessment of carotid bifurcation stenosis, using interactive volume rendering (VR), maximum intensity projection (MIP), and 2D transverse CT technique (t-CT).
Nineteen consecutive patients were prospectively studied with CTA and selective digital subtraction angiography (DSA). There were 13 men and 6 women from 51 to 84 years old (mean 70 years). Results of DSA were compared with those of interactive VR, MIP, and conventional t-CT results, using North American Symptomatic Carotid Endarterectomy Trial criteria for stenosis grading.
There were a total of 38 carotid bifurcations studied, with 9 mild, 10 moderate, and 15 severe stenoses and 4 occlusions. Overall agreement with DSA for VR was achieved in 76%. Eighty percent of the severe stenoses were correctly predicted by VR. The overall agreement between t-CT and DSA was 89%. MIP images, when analyzed independently, showed an overall agreement with angiography of only 71%. VR was not significantly different from MIP (p = 0.60). The difference between VR and t-CT had borderline significance (p = 0.09). MIP had significantly poorer agreement with angiography than t-CT (p = 0.02).
CTA has a high degree of accuracy for the assessment of carotid artery disease compared with catheter angiography. Interactive VR increases the accuracy of diagnosing carotid stenosis and decreases the number of unsatisfactory studies as compared with MIP. Further advances in computation speeds and improvements in software may dramatically alter the future use of VR for the communication of results to clinicians; however, careful analysis of transverse sections is essential to accurate CT interpretation.
Article: Correlation between US-PSV and 64-Row MDCTA with Advanced Vessel Analysis in the Quantification of 50-70% Carotid Artery Stenosis.[show abstract] [hide abstract]
ABSTRACT: Purpose. To correlate ultrasonographic peak systolic velocity (US-PSV) and 64-row multidetector computed tomography angiography (MDCTA) with advanced vessel analysis (AVA) software in the quantification of 50-70% carotid artery stenosis. Materials and methods. 199 consecutive patients (247 arteries) with internal carotid artery (ICA) or third proximal bifurcation stenosis. Each patient was studied by duplex US (DUS) and 64-row MDCTA with AVA software. Results. DUS showed PSV measurements less than 125 cm/s in 51 carotid stenosis and a value greater than this in 196 arteries. 64-row MDCTA AVA software showed a grade of stenosis less than 50% in 42 carotid arteries while a greater 70% was found in 4 carotid arteries; then, carotid arteries with stenosis percentage between 50% and 70% were 201. Linear regression analysis showed a good linear correlation (r = 0.88) between MDCTA-AVA software percentage stenosis and PSV: between 50% grade of stenosis and PSV value corresponding to 133,6 cm/sec and between 70% stenosis and PSV value corresponding to 268 cm/sec. The sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV) of this analysis were 93%, 82%, 97%, 75%, respectively. Conclusion. Linear correlation between PSV data and grade of stenosis from 50% to 70% obtained with 64-row MDCTA AVA software. Main PSV value corresponding to 50% and 70% grade of stenosis at AVA analysis.International journal of vascular medicine 01/2012; 2012:928638.