Computed Tomography Angiography for the Evaluation of Carotid Atherosclerotic Plaque

Abstract

Background and Purpose-The goal of this study was to determine the efficacy of CT angiography for the characterization of plaque morphology and composition in carotid atherosclerotic disease. Methods-Fifty-five patients undergoing carotid endarterectomy were imaged preoperatively with single-slice spiral CT angiography. One hundred sixty-five endarterectomy sections were examined histologically at selected levels through the distal common and proximal internal carotid arteries. Plaque density was measured (in Hounsfield units) on axial CT sections, and the presence or absence of ulceration was noted. These observations were compared with the histological findings at corresponding levels. Data were analyzed with 2-sample t tests and 1-way analysis of variance (ANOVA). Results-ANOVA testing showed a statistically significant decrease in CT attenuation values with increasing plaque lipid but with a very high standard deviation of values. No other histological factor showed a statistically significant link with CT attenuation. Plaque ulceration was detected by CT with a sensitivity of 60% and a specificity of 74%. Conclusions-Analysis

CT and Ultrasound in the Study of Ulcerated Carotid Plaque Compared with Surgical Results: Potentialities and Advantages of Multidetector Row CT Angiography

“…Distal ulcerations are uncommon. Furthermore, we demonstrated that ulcerations are much more common in fatty versus calcified plaques and confirmed the results of Walker et al 18 The relationship between plaque morphology and clinical behavior in the carotid circulation has been incompletely studied, but it has been demonstrated that cerebral infarcts are more frequent in patients with a lipid core than in patients without a lipid core. 33 The presence of a lipid core is significantly associated with cerebral infarction on MR imaging, and particular centrum semiovale infarcts are more frequent than cortical ones.…”

“…24 We demonstrated that MDCTA has a very a high sensitivity (93.75%) and specificity in detecting carotid artery plaque ulcerations. The sensitivity that we reported is higher compared with the works of Link et al, 41 Schwartz et al, 42 Debernardi et al, 24 Oliver et al, 10 and Walker et al 18 ; in these works, however, single-section CT scanners were used. We performed CTA examinations with a multidetector row scanner, and we studied each examination with axial and multiple postprocessed reconstructed images (MIP, MPR, SSD, and VR).…”

“…The attenuation was measured in Hounsfield units with the use of a circular or elliptical region of interest cursor in the predominant area of plaque at each level. 18 We divided ulcers in relation to their position, referred to the point of maximum stenosis 9 as follows: 1) proximal (proximal [upstream] to the point of maximum stenosis); 2) distal (distal [downstream] to the point of maximum stenosis); or 3) level (close to the point of maximum stenosis and therefore unable to be classified with certainty as proximal or distal). Grade of stenosis, carotid plaque surface morphology, presence or absence of ulceration, type of plaque, and plaque position were classified by 2 observers in consensus.…”

“…11,13 Plaque ulceration has been defined as "an intimal defect larger than 1000-m in width, exposing the necrotic core of the atheromatous plaque." 14 Conventional angiography has been considered the standard method for evaluating stenosis of the carotid artery, but it is not sufficiently reliable for detecting plaque ulceration 15,16 (angiography has a 46% sensitivity and a 74% specificity for detecting ulcerated plaques in large studies 17,18 ). Moreover, conventional angiography is also associated with an increased risk of thromboembolic events.…”

“…Moreover, conventional angiography is also associated with an increased risk of thromboembolic events. 19 Consequently, noninvasive techniques, such as ultrasound (US) echo color Doppler (US-ECD), 20,21 MR, 22,23 and CT angiography (CTA) 18,24 have been more and more frequently used to study carotid artery pathology.…”