Department of Vascular Surgery, University Hospital of Lyon, Lyon University, Lyon, France.
Stroke. 2012 Nov;43(11):3023-8. doi: 10.1161/STROKEAHA.112.662692. Epub 2012 Aug 23.
Although the ability of MRI to investigate carotid plaque composition is well established, the mechanism and the significance of plaque gadolinium (Gd) enhancement remain unknown. We evaluated clinical and histological significance of Gd enhancement of carotid plaque in patients undergoing endarterectomy for carotid stenosis.
Sixty-nine patients scheduled for a carotid endarterectomy prospectively underwent a 3-T MRI. Carotid plaque enhancement was assessed on T1-weighted images performed before and 5 minutes after Gd injection. Enhancement was recorded according to its localization. Histological analysis was performed of the entire plaque and of the area with matched contrast enhancement on MR images.
Gd enhancement was observed in 59% patients. Three types of carotid plaques were identified depending on enhancement location (shoulder region, shoulder and fibrous cap, and central in the plaque). Fibrous cap rupture, intraplaque hemorrhage, and plaque Gd enhancement was significantly more frequent in symptomatic than in asymptomatic patients (P=0.043, P<0.0001, and P=0.034, respectively). After histological analysis, Gd enhancement was significantly associated with vulnerable plaque (American Heart Association VI, P=0.006), neovascularization (P<0.0001), macrophages (P=0.030), and loose fibrosis (P<0.0001). Prevalence of neovessels, macrophages, and loose fibrosis in the area of Gd enhancement was 97%, 87%, and 80%, respectively, and was different depending on the enhancement location in the plaque. Fibrous cap status and composition were different depending on the type of plaque.
Gd enhancement of carotid plaque is associated with vulnerable plaque phenotypes and related to an inflammatory process.
尽管 MRI 检查颈动脉斑块成分的能力已得到充分证实，但斑块钆（Gd）增强的机制和意义仍不清楚。我们评估了颈动脉狭窄患者行颈动脉内膜切除术时颈动脉斑块 Gd 增强的临床和组织学意义。
69 例行颈动脉内膜切除术的患者前瞻性地接受了 3T MRI 检查。在 Gd 注射前和 5 分钟后进行 T1 加权图像评估颈动脉斑块增强。根据其定位记录增强情况。对整个斑块以及与 MR 图像上匹配的对比增强区域进行组织学分析。
59%的患者观察到 Gd 增强。根据增强位置（肩部区域、肩部和纤维帽以及斑块中心）确定了三种类型的颈动脉斑块。纤维帽破裂、斑块内出血和斑块 Gd 增强在症状性患者中明显比无症状患者更常见（P=0.043、P<0.0001 和 P=0.034）。经过组织学分析，Gd 增强与易损斑块（美国心脏协会 VI，P=0.006）、新生血管形成（P<0.0001）、巨噬细胞（P=0.030）和疏松纤维化（P<0.0001）显著相关。Gd 增强区域新生血管、巨噬细胞和疏松纤维化的患病率分别为 97%、87%和 80%，且取决于斑块内增强的位置而有所不同。纤维帽的状态和组成取决于斑块的类型。
颈动脉斑块的 Gd 增强与易损斑块表型相关，并与炎症过程有关。
