Impact Analysis of Different CT Configurations of Carotid Artery Plaque Calcifications on Cerebrovascular Events

Abstract

BACKGROUND AND PURPOSE: CT is considered the standard reference both for quantification and characterization of carotid artery calcifications. Our aim was to investigate the relationship among different types of calcium configurations detected with CT within the plaque with a novel classification and to investigate the prevalence of cerebrovascular events. MATERIALS AND METHODS:Seven hundred ninety patients (men = 332; mean age, 69.7 [SD,13] years; 508 symptomatic for cerebrovascular symptoms and 282 asymptomatic) who underwent computed tomography of the carotid arteries were retrospectively included in this institutional review board-approved study. The plaque was classified into 6 types according to the different types of calcium configurations as the following: type 1, complete absence of calcification within the plaque; type 2, intimal or superficial calcifications; type 3, deep or bulky calcifications; type 4, adventitial calcifications with internal soft plaque of ,2 mm thickness; type 5, mixed patterns with intimal and bulky calcifications; and type 6, positive rim sign. RESULTS:The highest prevalence of cerebrovascular events was observed for type 6, for which 89 of the 99 cases were symptomatic. Type 6 plaque had the highest degree of correlation with TIA, stroke, symptoms, and ipsilateral infarct for both sides with a higher prevalence in younger patients. The frequency of symptoms observed by configuration type significantly differed between right and left plaques, with symptoms observed more frequently in type 6 calcification on the right side (50/53; 94%) than on the left side (39/46; 85%, P , .001). CONCLUSIONS:We propose a novel carotid artery plaque configuration classification that is associated with the prevalence of cerebrovascular events. If confirmed in longitudinal analysis, this classification could be used to stratify the risk of occurrence of ischemic events.

Embolic strokes of undetermined source: a clinical consensus statement of the ESC Council on Stroke, the European Association of Cardiovascular Imaging and the European Heart Rhythm Association of the ESC

“… 37 , 38 On the other hand, other calcium configurations such as intimal or superficial calcifications, or type 3, deep, or bulky calcifications, are rarely associated with the occurrence of cerebrovascular events. 39 …”

International Union of Angiology (IUA) consensus paper on imaging strategies in atherosclerotic carotid artery imaging: From basic strategies to advanced approaches

“…Among the multiple parameters that have been indicated as responsible for an increased vulnerability, conflicting results have emerged in the identification of a role for calcium. Emerging research has suggested various mechanisms in calcium deposition leading to different phenotypes of carotid plaque calcification [97][98][99][100][101]. Yang et al investigated the association between calcium configurations and ulceration with IPH, demonstrating that superficial, multiple, and thin calcifications were associated with IPH.…”

Risk factors for recurrent ischemic events in symptomatic carotid artery stenosis on CT angiography

“…Recent reports showed that rim sign (plaque adventitial calcification) or ulceration on computed tomography angiography (CTA) is correlated with intraplaque hemorrhage (IPH) or symptomatic carotid artery stenosis. 1,[4][5][6] We aim to investigate the association of recurrent ischemic events in symptomatic mild to moderate carotid stenosis with specific plaque findings on CTA.…”

“…The interactive window/level setting was usually set at W850.L300. 6 The images were evaluated by two blinded neurosurgeons (TT and KY). CTA markers included the degree of stenosis (NASCET criteria) and presence of rim sign, ulceration, and intraluminal thrombus.…”

“…A positive rim sign was defined as adventitial calcification (< 2 mm thickness) with internal soft plaque (> 2 mm thickness) (Figure 1). 1,[4][5][6] Ulceration was determined as a depression of 1 mm or more. 7 Variables were expressed as means ± SD or the number of patients (%), as appropriate.…”