Major carotid plaque surface irregularities correlate with neurologic symptoms
Major carotid plaque surface irregularities correlate with neurologic symptoms
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DOI：
10.1067/mva.2002.121210
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发表时间：
2002-04-01
影响因子：
4.3
通讯作者：
Rapp, JH
中科院分区：
文献类型：
--
作者：
Troyer, A;Saloner, D;Rapp, JH
目的：许多研究已将颈动脉斑块表面异常与卒中风险联系起来，但由于现有成像手段对斑块表面形态的分辨能力有限，这种关系被掩盖了。为了解决这个问题，我们进行了一项前瞻性研究，将患者出现的神经系统症状与高分辨率磁共振成像(MRI；200um)研究的同侧斑块表面凹陷和台阶、管腔形状和造成狭窄的斑块块的位置相关联。100例患者，女性17例，男性83例，年龄45~81岁，平均68岁。手术指征为短暂性脑缺血发作(TIA)或中风者45例，无症状55例。50例患者进行了血管造影。颈动脉斑块被“整块”移除并放置在Gd中。在西门子交响乐1.5T扫描仪中掺入生理盐水用于成像，该扫描仪带有定制的发射-接收射频线圈。得到的切片厚度为200 PM，平面分辨率为200 PM×200微米。使用美国国立卫生研究院影像软件对MRI数据和血管造影术进行复习，并取得一致意见。表面不规则性被归类为牙缘或溃疡，并用电子卡尺测量。在最大狭窄处确定管腔形状，将“切片”设置为与管腔轴线成90度角。记录最大狭窄的位置。在颈内动脉，斑块主要位于分流管壁或非分流管壁。平均最大狭窄为81.5%+/-12.0%。有80个斑块表面轮廓不规则。35个斑块被分级为具有主要表面轮廓不规则，45个斑块被分级为具有轻微不规则。主要表面不规则性与短暂性脑缺血发作或卒中显著相关(P<；.01)。血管造影可发现不规则斑块，但其大小的不规则性被低估(P<；.01)。只有28%的斑块有圆形管腔，50%的斑块有椭圆形管腔，22%的斑块有新月形或多小叶管腔。狭窄最大的斑块位于颈内动脉82块，斑块分叉处17块，颈总动脉1块。结论：MRI对颈动脉斑块的亚毫米分辨率显示了颈动脉斑块表面的不规则性，但只有与TIA或卒中有关的主要不规则性的存在。管腔形状和斑块位置似乎不能预测卒中风险，但可能会影响确定狭窄程度的成像准确性。这些数据进一步明确了斑块不规则性与动脉粥样硬化栓子引起的脑血管症状的关系。
Purpose: Many studies have linked carotid plaque surface irregularities with stroke risk, but this relationship has been obscured by the limited ability of available imaging modalities to resolve plaque surface morphology. To address this issue, we performed a prospective study correlating the presenting neurologic symptoms of patients with high-resolution magnetic resonance imaging (MRI; 200 mum) studies of ipsilateral plaque surface invaginations and ledges, lumen shape, and the location of the plaque bulk creating the stenosis.Methods. One hundred patients, 17 women and 83 men, 45 to 81 years old (mean, 68 years) underwent surgery Forty-five patients had a transient ischemic attack (TIA) or stroke as the indication for surgery, and 55 patients had no symptoms. Angiograms were obtained in 50 patients. Carotid plaques were removed "en bloc" and placed in gadolinium. doped saline for imaging in a Siemens Symphony, 1.5T scanner with a custom-built transmit-receive radiofrequency coil. The resulting slice thickness was 200 pm, with 200 pm by 200 mum in plane resolution. The MRI data and angiograms were reviewed by using National Institutes of Health Image software and read by consensus. A surface irregularity was categorized as a ledge or ulcer and measured by using electronic calipers. Luminal shape was determined at the point of maximal stenosis with a "slice" set at 90degrees to the lumen axis. The location of the maximal stenosis was recorded. In the internal carotid artery, plaque bulk was designated to be on the flow divider wall or non-flow divider wall.Results. The mean maximal stenosis was 81.5% +/- 12.0%. Surface contour irregularities were found in 80 plaques. Thirty-five plaques were graded as having major surface contour irregularities, and 45 plaques were graded as having minor irregularities. There was a significant correlation between major surface irregularity and TIA or stroke (P < .01). Irregular plaques were identified with angiography, but the irregularity in size was underestimated (P < .01). Only 28% of plaques had circular lumens; 50% had elliptical lumens, and 22% had either crescentic or multi-lobular lumens. The maximal stenosis was located in the internal carotid artery in 82 plaques, the bifurcation in 17 plaques, and the common carotid artery in one plaque.Conclusion: Surface irregularities were revealed by means of submillimeter resolution of the carotid plaques with MRI to be common, but only the presence of major irregularities correlated with the patient having TIA or stroke. Lumen shape and plaque location did not appear to predict stroke risk, but may effect imaging accuracy in determining the degree of stenosis. These data further define the relationship of plaque irregularity and cerebrovascular symptoms caused by atheroemboli.