Yu Chen MD, Presenter: Nothing to Disclose

Huadan Xue MD, Abstract Co-Author: Nothing to Disclose

Wei Liu, Abstract Co-Author: Nothing to Disclose

Hao Sun MD, Abstract Co-Author: Nothing to Disclose

Xuan Wang MD, Abstract Co-Author: Nothing to Disclose

Zhengyu Jin MD, Abstract Co-Author: Nothing to Disclose

The authors performed a study with dual energy CT angiography in evaluating the degree of carotid artery stenosis, comparing the 3D TOF MRA and using digital substraction angiography as the reference standard.

Totally 19 patients received a dual energy CT angiography scan, along with a cerebral MRA and DSA examination Dual energy software was used for bone and hard plaque removal. Seven anatomical segments were described for each internal carotid artery. Ratings were based on a 1-4 scale for the DE-CTA maximum intensity projection (MIP) image: 1=poor,gaps within the vessel；2=insufficient, large bone remants and or severe artifical lumen reducion of the vessel;3=sufficient, small bone remnants and or mild lumen alterations; 4=excellent,no bone remnants and or no lumen alteration. Lesions were categorized as 0%, mild (1-49%), moderate (50%-69%), severe (70%-99%), and occluded .  Accuracy, sensitivity,specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for Dual energy CTA and MRA. Wilcoxon tests were used to determine significant differences (p<0.05) between the diagnostic performance of the three modalities.

Totally 255 arterial segments except image quality rating one(n=10) or having aneurysm (n=1) in  dual energy CTA were evaluated. None of the the three modalities detected occlusion . For stenosis grading, accuracy, sensitivity, specificity, PPV and NPV were 98%,100%,98%,80% and 100% respectively, at dual energy CTA；98%,100%,96%,69% and 100% respectively, at 3D TOF MRA. Using a 50% cutoff value for stenosis, sensitivity, specificity, PPV and NPV were 100%, 96%, 36% and 100% respectively, at dual energy CTA；60%, 98%,43% and 98% respectively, at 3D TOF MRA. There were significant differences between dual energ CTA with DSA(z=-2.872, p=0.005), and MRA with DSA(z=-2.608,p=0.009).But there were no significant differences between MRA and DSA (p=0.429).  

Dual energy CT with bone and calcifications removal allow improved diagnostic evaluation of the degree of internal carotid stenosis in substantially equal to 3D TOF MRA and DSA, but may exaggerate the degree of the stenosis, especially involving mild and severe stenosis.

Dual energy CT has the potential to distinguish iodine from bone or calcifications, and it is a powerful, noninvasive diagnostic tool for evaluating carotid artery disease.

Chen, Y, Xue, H, Liu, W, Sun, H, Wang, X, Jin, Z, Dual-Energy CT Angiography in Evaluating the Degree of Carotid Stenosis Using Bone and Hard Plaque Removal: Compared with MRA and DSA.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11015878.html