Yuan Chun, Zhang Shao-xiong, Polissar Nayak L, Echelard Denise, Ortiz Geraldo, Davis Joseph W, Ellington Elizabeth, Ferguson Marina S, Hatsukami Thomas S
Department of Radiology, University of Washington, Seattle 98195, USA.
Circulation. 2002 Jan 15;105(2):181-5. doi: 10.1161/hc0202.102121.
High-resolution MRI has been shown to be capable of distinguishing intact, thick fibrous caps from thin and ruptured caps in human carotid atherosclerosis in vivo. The aim of this study was to determine whether MRI identification of fibrous cap thinning or rupture is associated with a history of recent transient ischemic attack (TIA) or stroke.
Fifty-three consecutive patients (mean age, 71 years; 49 male) scheduled for carotid endarterectomy were recruited after obtaining informed consent. Twenty-eight subjects had a recent history of TIA or stroke on the side appropriate to the index carotid lesion, and 25 were asymptomatic. Preoperative carotid MRI was performed in a 1.5-T GE Signa scanner that generated T(1)-, PD-, and T(2)-weighted and three-dimensional time-of-flight images. Using previously reported MRI criteria, the fibrous cap was categorized as intact-thick, intact-thin, or ruptured for each carotid plaque by blinded review. There was a strong and statistically significant trend showing a higher percentage of symptomatic patients for ruptured caps (70%) compared with thick caps (9%) (P=0.001 Mann-Whitney test for cap status versus symptoms). Compared with patients with thick fibrous caps, patients with ruptured caps were 23 times more likely to have had a recent TIA or stroke (95% CI=3, 210).
MRI identification of a ruptured fibrous cap is highly associated with a recent history of TIA or stroke. Ongoing prospective studies will determine the predictive value fibrous cap characteristics, as visualized by MRI, for risk of subsequent ischemic events.
高分辨率磁共振成像（MRI）已被证明能够在体内区分人类颈动脉粥样硬化中完整、增厚的纤维帽与薄的和破裂的纤维帽。本研究的目的是确定MRI识别纤维帽变薄或破裂是否与近期短暂性脑缺血发作（TIA）或中风病史相关。
在获得知情同意后，连续招募了53例计划行颈动脉内膜切除术的患者（平均年龄71岁；49例男性）。28例受试者在与索引颈动脉病变相应的一侧有近期TIA或中风病史，25例无症状。在1.5-T的GE Signa扫描仪上进行术前颈动脉MRI检查，该扫描仪生成T（1）加权、质子密度加权、T（2）加权和三维时间飞跃图像。采用先前报道的MRI标准，通过盲法评估将每个颈动脉斑块的纤维帽分类为完整增厚、完整变薄或破裂。存在一个强烈且具有统计学意义的趋势，即与增厚的纤维帽（9%）相比，破裂纤维帽的有症状患者比例更高（70%）（纤维帽状态与症状的Mann-Whitney检验，P = 0.001）。与纤维帽增厚的患者相比，纤维帽破裂的患者近期发生TIA或中风的可能性高23倍（95%可信区间 = 3, 210）。
MRI识别出破裂的纤维帽与近期TIA或中风病史高度相关。正在进行的前瞻性研究将确定MRI显示的纤维帽特征对后续缺血事件风险的预测价值。
