Association of plaque compositions and stenosis patterns in carotid bifurcation using MR imaging

Abstract

Objectives: To investigate the relationship between plaque compositions and stenosis patterns in patients with atherosclerotic plaques at the carotid bifurcation using magnetic resonance (MR) imaging.

Methods: One hundred and four carotid arteries with stenosis over 50% from 75 symptomatic stroke patients (64 male and 11 female; mean age 58·2±13·3 years) were studied. Plaque compositions were analyzed by high-resolution MR imaging using a 3·0T MR with a surface coil. Stenosis patterns were classified into three types according to contrast-enhanced MR angiography images. Correlations of different components of plaques and stenosis patterns were analyzed.

Results: One hundred and four carotid arteries were analyzed. Three stenosis patterns were identified. The prevalences of the three patterns are as follows: type I (total occlusion) at 27·9% (29/104), type II (local plaque with normal distant flow) at 56·7% (59/104), and type III (local plaque with impaired distant flow) at 15·4% (16/104). The contingency coefficients between stenosis pattern and stability, intraplaque hemorrhage (IPH), lipid necrotic core (LNC), and ulcer were 0·383 (P = 0·000), 0·290 (P = 0·008), 0·439 (P = 0·000), and 0·388 (P = 0·000), respectively. Multinomial analysis showed that compared with type III vessels, type I vessels were more likely to contain IPH (P = 0·019) and less likely to contain large LNC (P = 0·001); type II vessels had a greater possibility for containing IPH than type III vessels (P = 0·009); LNC was more likely to be found in type II than in type I vessels (P = 0·000). No significant difference was found in ulceration prevalence between type II and type III vessels (P = 0·058).

Conclusions: The current study demonstrated positive associations between stenosis patterns and plaque compositions.

Keywords:

• Carotid
• High-resolution MR imaging
• Stenosis pattern
• Vulnerable plaque

This work was supported by a grant from the Beijing Natural Science Foundation, China (No. 7092018), a grant from Beijing Nova Program (2009A30), and Youth Research Grant of Beijing Municipal Health Bureau (QN2010-016).