Department of Neurosurgery, Nagasaki University School of Medicine, 1-7-1, Sakamoto, Nagasaki 852-8501, Japan.
Stroke. 2012 Feb;43(2):393-8. doi: 10.1161/STROKEAHA.111.635953. Epub 2011 Nov 17.
Recent studies have investigated plaque morphology to determine patients who are at high risk of carotid atherosclerosis. In this study, we investigated whether a difference in dynamic enhancement pattern in plaque components could be useful to assess plaque stability with multidetector CT angiography.
Fifty-nine lesions with moderate to severe carotid atherosclerosis in 51 patients (33 symptomatic, 18 asymptomatic) were consecutively included. Early- and delayed-phase images were obtained in 3 equivalent axial slices with multidetector CT angiography. Hounsfield units (HU) in the early phase were subtracted from those in the delayed phase in plaques (ΔHU) and compared with clinical features, MRI-based plaque characteristics, and histological findings with 20 surgical specimens acquired from carotid endarterectomy.
The ΔHU was significantly higher in asymptomatic than that in symptomatic presentation (P=0.02). With MRI, a higher ΔHU was negatively correlated with signal intensity on T1-weighted imaging (r=-0.56, P<0.0001). Histology confirmed that ΔHU was positively correlated with fibrous tissue (r=0.67, P=0.001) and negatively correlated with a lipid-rich necrotic core with hemorrhage (r=-0.70, P<0.001). Moreover, less neovascularization and inflammation was found in plaques with a higher ΔHU.
Delayed-phase images provide information regarding the dynamic change in contrast media from the early arterial phase. An increase in HU from the early phase on multidetector CT angiography indicates plaque stability with more fibrous tissue and a less lipid-rich necrotic core, intraplaque hemorrhage, and neovascularization.
近期研究已经调查了斑块形态，以确定颈动脉粥样硬化高危患者。在本研究中，我们研究了斑块成分的动态增强模式差异是否可用于通过多排 CT 血管造影评估斑块稳定性。
连续纳入 51 例（33 例有症状，18 例无症状）中 59 处中重度颈动脉粥样硬化病变。使用多排 CT 血管造影获得 3 个相同的轴位层面的早期和延迟期图像。在斑块中，从早期相的 Hounsfield 单位（HU）中减去延迟相的 HU（ΔHU），并与 20 例颈动脉内膜切除术获得的临床特征、基于 MRI 的斑块特征和组织学发现进行比较。
无症状组的 ΔHU 明显高于有症状组（P=0.02）。使用 MRI，较高的 ΔHU 与 T1 加权成像上的信号强度呈负相关（r=-0.56，P<0.0001）。组织学证实 ΔHU 与纤维组织呈正相关（r=0.67，P=0.001），与富含脂质的坏死核心伴出血呈负相关（r=-0.70，P<0.001）。此外，在 ΔHU 较高的斑块中发现较少的新生血管和炎症。
延迟期图像提供了关于对比剂在早期动脉期的动态变化的信息。多排 CT 血管造影早期相 HU 的增加表明斑块稳定性增加，纤维组织增多，富含脂质的坏死核心、斑块内出血和新生血管减少。
