Introduction: Carotid plaque showing hyperintensity on T1-weighted magnetic resonance imaging reflects unstable plaque consisting of lipid/necrosis and/or hemorrhage and has been reported as a risk factor for embolic complications during carotid endarterectomy (CEA) or stenting. However, it remains unclear whether hyperintense plaque is related to stroke events. Thus, we evaluated the difference in the intraplaque signal between asymptomatic and symptomatic patients with carotid stenosis.
Methods: We prospectively collected and retrospectively analyzed 68 patients who underwent CEA (age, 53-79 years; 61 men and 7 women; 52 symptomatic and 16 asymptomatic). Using a fast spin-echo technique at 1.5 T, the contrast ratio (CR) of carotid plaque to adjacent muscle was calculated on axial images based on maximum plaque size. Differences in patient characteristics (age, sex, hypertension, dyslipidemia, diabetic mellitus, and degree of stenosis) as well as CRs between symptomatic and asymptomatic patients were examined using Fisher’s exact test, the Mann-Whitney test, and multivariable logistic regression analysis.
Results: The CRs of the carotid plaque were significantly higher in the symptomatic group than in the asymptomatic group (0.97-2.32 [median, 1.55] and 0.95-2.01 [1.32], respectively; p = 0.026). In addition, age, hypertension, and stenosis degree were significantly higher in the former than in the latter (p = 0.013- 0.003). Multivariate logistic regression analysis revealed that only hypertension and CRs of the plaque were independent risks of symptomatic stenosis (odds ratio, 11.0 and 2.7; 95% confidence interval, 2.0-62.0 and 1.1-6.6; p = 0.007 and 0.025; respectively).
Conclusion: CRs of the carotid plaque as well as hypertension were significantly and independently related with symptomatic patients, suggesting that hyperintense plaque can be a risk factor of stroke events in patients with carotid stenosis.