Preoperative Diagnosis of Carotid Artery Stenosis

Abstract

Background and Purpose-Carotid endarterectomy has been shown to be beneficial in symptomatic patients with a severe stenosis (70% to 99%) of the internal carotid artery (ICA). Digital subtraction angiography (DSA) is the standard of reference in the diagnosis of carotid artery stenosis but has a relatively high complication rate. In a diagnostic study we investigated the accuracy of noninvasive testing compared with DSA. Methods-In a prospective diagnostic study we performed duplex ultrasound (DUS), magnetic resonance angiography (MRA), and DSA on 350 consecutive symptomatic patients. Stenoses were measured with the observers blinded for clinical information and other test results. Separate and combined test results of DUS and MRA were compared with the reference standard DSA. Only the stenosis measurements of the arteries on the symptomatic side were included in the analyses. Results-DUS analyzed with previously defined criteria resulted in a sensitivity of 87.5% (95% CI, 82.1% to 92.9%) and a specificity of 75.7% (95% CI, 69.3% to 82.2%) in identifying severe ICA stenosis (70% to 99%). Stenosis measurements on MRA yielded a sensitivity of 92.2% (95% CI, 86.2% to 96.2%) and a specificity of 75.7% (95% CI, 68.6% to 82.5%). When we combined MRA and DUS results, agreement between these 2 modalities (84% of patients) gave a sensitivity of 96.3% (95% CI, 90.8% to 99.0%) and a specificity of 80.2% (95% CI, 73.1% to 87.3%) for identifying severe stenosis. Conclusions-MRA showed a slightly better accuracy than DUS in the diagnosis of carotid artery stenosis. To achieve the best accuracy, however, both tests should be performed subsequently.

Accurate, practical and cost-effective assessment of carotid stenosis in the UK

“…88,96,103,114,115 The largest study had 313 patients. 104 The 41 studies included a combined total of 2404 patients. Twelve studies did not report the average age of the patients.…”

“…121 This study measured stenosis using the ECST method, 72 whereas the other papers all used the NASCET method. 93,104,120 There were too few data in the ROC plot for 50-69% stenosis to say whether the points lay on a curve or not ( Figure 14). The results of testing for threshold effects using correlation coefficients are given in of 0-49% stenosis or occluded is very high, and this meta-analysis includes a possible outlier 93 ).…”

“…Only two papers used only one artery per patient. 34,104 There was no evidence that the two carotid arteries from one patient can be analysed as though they come from two different patients. This point will be explored It was disappointing that, of the large number of potentially relevant papers identified (over 600), so few could be included in the meta-analysis.…”

“…Furthermore, the situation may be complicated by the fact that only two of the studies used one artery per patient. 34,104 The other studies that screened patients by US only required that one artery had significant stenosis, and the other artery could have any degree of stenosis and was often also included in the study. In the studies where authors stated that only patients with significant disease were included, some of the patients had both a diseased artery and a healthy artery.…”

Accuracy Analysis of Magnetic Resonance Angiography and Computed Tomography Angiography Using a Flow Experimental Model

“…TOF MRA provides information on vessel conformation and functional information, and allows high definition images of blood vessels within a relatively short time. These attributes have spurred its popularity [10][11][12][13]. TOF MRA produces a low signal by saturating the signal from a stationary object, and uses blood flow to yield a contrast difference between stationary anatomical objects and blood vessels [13].…”