Lal Brajesh K, Hobson Robert W, Hameed Meera, Pappas Peter J, Padberg Frank T, Jamil Zafar, Durán Walter N
Division of Vascular Surgery, Department of Surgery, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, NJ 07101-7190, USA.
Ann Vasc Surg. 2006 Mar;20(2):167-74. doi: 10.1007/s10016-006-9000-8. Epub 2006 Mar 30.
Intraplaque hemorrhage, enlarging lipid cores, and their proximity to the flow lumen are important determinants of carotid plaque rupture and neurological complications. We developed an image-analysis method for B-mode ultrasound, pixel distribution analysis (PDA), for preprocedural identification of these high-risk features in carotid plaques. This technique may improve selection of patients for carotid endarterectomy and carotid artery stenting. Forty-two patients with high-grade carotid stenosis in 45 arteries, 18 symptomatic and 27 asymptomatic, underwent preoperative ultrasound. Intraplaque hemorrhage, lipid, fibromuscular tissue, calcium, lipid core area, and distance from the flow lumen were quantified using pixel intensities of tissues in control subjects. These findings were contrasted between symptomatic and asymptomatic plaques and correlated with histology. Inter- and intraobserver variabilities were determined for this technique. Pixel intensities of control tissues were discrete and significantly different from each other (median: blood 0, lipid 27, muscle 45.5, fibrous tissue 204, and calcium 245). There was more intraplaque hemorrhage (p<0.001) and lipid (p=0.002) but less calcium (p<0.001) within symptomatic plaques. Lipid cores were larger (p=0.005) and their distance from the flow lumen was lower (p=0.01) in symptomatic plaques. Intraplaque hemorrhage, lipid, fibromuscular tissue, calcium, lipid core size, and distance from flow lumen measured by PDA correlated with histology. No significant inter- or intraobserver variabilities were observed in these measurements. PDA accurately identified more intraplaque hemorrhage and lipid, less calcium, and larger lipid cores located closer to the flow lumen in symptomatic patients with carotid stenosis. These data indicate that PDA may be used to identify high-risk carotid atherosclerotic plaques and thereby improve the selection of patients requiring treatment.
斑块内出血、脂质核心增大及其与血流腔的接近程度是颈动脉斑块破裂和神经并发症的重要决定因素。我们开发了一种用于B型超声的图像分析方法，即像素分布分析（PDA），用于术前识别颈动脉斑块中的这些高危特征。该技术可能会改善颈动脉内膜切除术和颈动脉支架置入术患者的选择。45条动脉中存在高级别颈动脉狭窄的42例患者，18例有症状，27例无症状，接受了术前超声检查。使用对照受试者组织的像素强度对斑块内出血、脂质、纤维肌肉组织、钙、脂质核心面积以及与血流腔的距离进行量化。对有症状和无症状斑块的这些发现进行了对比，并与组织学相关联。确定了该技术的观察者间和观察者内变异性。对照组织的像素强度是离散的，且彼此之间有显著差异（中位数：血液0、脂质27、肌肉45.5、纤维组织204和钙245）。有症状斑块内的斑块内出血（p<0.001）和脂质（p=0.002）更多，但钙（p<0.001）更少。有症状斑块中的脂质核心更大（p=0.005）且其与血流腔的距离更近（p=0.01）。通过PDA测量的斑块内出血、脂质、纤维肌肉组织、钙、脂质核心大小以及与血流腔的距离与组织学相关。在这些测量中未观察到显著的观察者间或观察者内变异性。PDA准确地识别出有症状的颈动脉狭窄患者中更多的斑块内出血和脂质、更少的钙以及更靠近血流腔的更大脂质核心。这些数据表明，PDA可用于识别高危颈动脉粥样硬化斑块，从而改善需要治疗患者的选择。
