Carotid Plaque Neovascularization and Hemorrhage Detected by MR Imaging are Associated with Recent Cerebrovascular Ischemic Events

Abstract

BACKGROUND AND PURPOSE Pathologic studies suggest that neovascularization and hemorrhage are important features of plaque vulnerability for disruption. Our aim was to determine the associations of these features in carotid plaques with previous cerebrovascular ischemic events by using high-resolution CE-MRI. MATERIALS AND METHODS Forty-seven patients (36 men; mean age 72.5 ± 10 years) underwent CE-MRI and MRA examinations for carotid plaque at 3T. IPH presence was recorded. Neovascularity was categorized by the degree of adventitial enhancement (0, absent; 1, <50%; 2, ≥50%). Reader variability was assessed by using weighted κ. Associations with events were determined by using multivariable logistic regression. RESULTS Intra- and inter-reader agreement for grading adventitial enhancement were good to excellent. IPH was present in 49% of patients and was associated with events (P = .03). Patients grouped by categories 0, 1, and 2 adventitial enhancement had increasing frequencies of events (14% category 0, 48% category 1, 65% category 2; P = .02). Events were associated with IPH (OR, 10.18; 95% CI, 1.42–72.21) and adventitial enhancement (compared with category 0: OR, 14.90, 95% CI, 0.98–225.93 for category 1; OR, 51.17, 95% CI, 3.4–469.8 for category 2) after controlling for age, sex, cardiovascular risk factors, wall thickness, and stenosis. Stenosis was not associated with events. CONCLUSIONS Adventitial enhancement and IPH are independently associated with previous events and may provide important insight into stroke risk not achievable by stenosis.

Differential Features of Culprit Intracranial Atherosclerotic Lesions: A Whole‐Brain Vessel Wall Imaging Study in Patients With Acute Ischemic Stroke

“…Studies of carotid atherosclerotic plaques have suggested that contrast enhancement of plaques is a marker of neovascularization and inflammation 26, 27. Also, a postmortem study found that neovascularity in intracranial atherosclerotic plaque is associated with infarct 28.…”

Imaging of the Carotid Artery Vulnerable Plaque

“…MRI also can assess the presence of neovasculature in carotid artery plaques [82][83][84][85]. A recent study by Gaens et al [85] showed that dynamic contrast-enhanced MR of carotid atherosclerotic plaques can assess plaque neovasculature and that the Patlak model is well-suited for describing carotid plaque enhancement; the authors found that the K(trans) is an indicator of plaque microvasculature (validated by histology) and that the reproducibility of K(trans) was good.…”

Intracranial Vessel Wall MRI: Principles and Expert Consensus Recommendations of the American Society of Neuroradiology

“…Contrast enhancement of carotid bulb atherosclerotic plaque occurs preferentially in the fibrous cap and adventitia (though sometimes in the middle of the plaque) and is a marker of inflammation and neovascularization. 25,[67][68][69] A postmortem study 59 found that neovascularity in MCA atherosclerotic plaque was associated with ipsilateral infarction. VW-MR imaging studies 19,70,71 have shown that intracranial plaque enhancement is associated with recent infarction in the territory of the plaque.…”