Brinjikji Waleed, Michalak Gregory, Kadirvel Ramanathan, Dai Daying, Gilvarry Michael, Duffy Sharon, Kallmes David F, McCollough Cynthia, Leng Shuai
1 Department of Radiology, Mayo Clinic, USA.
2 Department of Neurosurgery, Mayo Clinic, USA.
Interv Neuroradiol. 2017 Jun;23(3):279-284. doi: 10.1177/1591019917694479. Epub 2017 Jan 1.
Background and purpose Because computed tomography (CT) is the most commonly used imaging modality for the evaluation of acute ischemic stroke patients, developing CT-based techniques for improving clot characterization could prove useful. The purpose of this in-vitro study was to determine which single-energy or dual-energy CT techniques provided optimum discrimination between red blood cell (RBC) and fibrin-rich clots. Materials and methods Seven clot types with varying fibrin and RBC densities were made (90% RBC, 99% RBC, 63% RBC, 36% RBC, 18% RBC and 0% RBC with high and low fibrin density) and their composition was verified histologically. Ten of each clot type were created and scanned with a second generation dual source scanner using three single (80 kV, 100 kV, 120 kV) and two dual-energy protocols (80/Sn 140 kV and 100/Sn 140 kV). A region of interest (ROI) was placed over each clot and mean attenuation was measured. Receiver operating characteristic curves were calculated at each energy level to determine the accuracy at differentiating RBC-rich clots from fibrin-rich clots. Results Clot attenuation increased with RBC content at all energy levels. Single-energy at 80 kV and 120 kV and dual-energy 80/Sn 140 kV protocols allowed for distinguishing between all clot types, with the exception of 36% RBC and 18% RBC. On receiver operating characteristic curve analysis, the 80/Sn 140 kV dual-energy protocol had the highest area under the curve for distinguishing between fibrin-rich and RBC-rich clots (area under the curve 0.99). Conclusions Dual-energy CT with 80/Sn 140 kV had the highest accuracy for differentiating RBC-rich and fibrin-rich in-vitro thrombi. Further studies are needed to study the utility of non-contrast dual-energy CT in thrombus characterization in acute ischemic stroke.
背景与目的 由于计算机断层扫描（CT）是评估急性缺血性中风患者最常用的成像方式，因此开发基于CT的技术以改善血栓特征描述可能会很有用。这项体外研究的目的是确定哪种单能量或双能量CT技术能在红细胞（RBC）和富含纤维蛋白的血栓之间提供最佳区分。材料与方法 制作了七种纤维蛋白和RBC密度不同的血栓类型（高纤维蛋白密度和低纤维蛋白密度的90% RBC、99% RBC、63% RBC、36% RBC、18% RBC和0% RBC），并通过组织学方法验证其成分。每种血栓类型制作10个，并使用第二代双源扫描仪，采用三种单能量（80 kV、100 kV、120 kV）和两种双能量方案（80/Sn 140 kV和100/Sn 140 kV）进行扫描。在每个血栓上放置感兴趣区域（ROI）并测量平均衰减。计算每个能量水平下的受试者操作特征曲线，以确定区分富含RBC的血栓和富含纤维蛋白的血栓的准确性。结果 在所有能量水平下，血栓衰减均随RBC含量增加。80 kV和120 kV的单能量以及80/Sn 140 kV的双能量方案能够区分除36% RBC和18% RBC之外的所有血栓类型。在受试者操作特征曲线分析中，80/Sn 140 kV双能量方案在区分富含纤维蛋白的血栓和富含RBC的血栓方面，曲线下面积最大（曲线下面积为0.99）。结论 80/Sn 140 kV双能量CT在区分体外富含RBC和富含纤维蛋白的血栓方面具有最高的准确性。需要进一步研究以探讨非增强双能量CT在急性缺血性中风血栓特征描述中的应用价值。
