目的： 探索3.0T动态增强磁共振成像（dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI）评价颈动脉粥样硬化斑块稳定性的效能。方法： 对66例超声检查显示颈动脉内膜增厚 ≥2 mm的患者,行颈动脉磁共振管壁成像（vessel wall magnetic resonance imaging,VW-MRI）及DCE-MRI扫描,并依据MRI修正的美国心脏协会（American Heart Association,AHA）斑块分型标准,对颈动脉斑块进行分型与定性（Ⅳ~Ⅵ型为不稳定斑块,余为稳定斑块）,计算DCE-MRI药代动力学参数（K^trans、k_ep、v_e和v_p）,评估各参数与斑块分型、斑块稳定性间的相关性,以及各参数区分稳定斑块与不稳定斑块的效能。结果： K^trans、k_ep均与MRI 修正的AHA分型（Ⅲ~Ⅵ型）呈显著正相关（ρ=0.532, P<0.001; ρ=0.409, P<0.001）。K^trans、k_ep可区分稳定斑块与易损斑块,其最佳临界值分别为0.043/min（此时诊断灵敏度为83%,特异度为100%）和0.741/min（诊断灵敏为77%,特异度为91%）。结论： DCE-MRI药代动力学参数K^trans、k_ep可定量评估颈动脉斑块的稳定性,是斑块危险性分层的影像学标志物。

Objective: To explore the ability of 3.0T dynamic contrast-enhanced MR imaging (DCE-MRI) in identi-fying the vulnerability of carotid atherosclerotic plaques. Methods: From September 2016 to June 2017, 66 patients with carotid intima thickening ≥2 mm were enrolled in this study. All participants underwent vessel wall MR imaging (VW-MRI) and DCE-MRI. With the classification of plaques according to MRI-modified AHA Lesion-Type (LT), pharmacokine-tic parameters (PPs) of DCE-MRI were measured, including K^trans, k_ep, v_e and v_p. Correlations between PPs and LTs and the ability of these parameters to distinguish stable and vulnerable plaques suspected on MRI were assessed. Results: Signi-ficant positive correlation between K^trans and LT Ⅲ to Ⅵ was found (P=0.532, P<0.001), so as was the correlation between k_ep and LT Ⅲ to Ⅵ (P=0.409, P<0.001). Stable and vulnerable plaques suspected on MRI could potentially be distinguished by K^trans (sensitivity 83%, specificity 100%) and k_ep (sensitivity 77%, specificity 91%). Conclusions: K^trans and k_ep from DCE-MRI can provide quantitative information for the differentiation of vulnerable plaques suspected on MRI from stable ones. These two parameters could be adopted as imaging markers for plaque characterization and risk stratification.