Background

Tandem occlusions can complicate medical and endovascular stroke treatment. To identify these occlusions, computed tomography angiography (CTA) represents the best imaging modality. However, CTA is still not initially performed in some patients not admitted directly to stroke centers. Early identification of an additional occlusion of the proximal extracranial internal carotid artery may improve the best suitable treatment strategy. The purpose of this study was to find a valuable threshold of thrombus attenuation in a non-contrast head CT (NCCT) scan to facilitate a safe diagnosis of tandem occlusions.

Materials and methods

Consecutive patients with acute middle cerebral artery (MCA) occlusions who underwent endovascular treatment were identified from our registry of neuroendovascular interventions. Thrombus attenuations of the affected MCA and contralateral vessel were measured by NCCT. To compare individual baseline blood attenuations, the difference between the thrombus attenuation and the contralateral MCA attenuation (referred to as ΔTM) was calculated.

Results

Three hundred and twenty-five patients were included. There was a highly significant difference between mean thrombus attenuation with isolated MCA occlusion and additional extracranial internal carotid artery (ICA) occlusion (49.9 ± 8 vs. 56.2 ± 10 Hounsfield units (HU); P < 0.001). The area under the receiver operating characteristic curve of ΔTM was 0.72. The optimal threshold value was 13.5 HU, with a sensitivity of 67.5% and a specificity of 68.6%.

Conclusion

Despite a significant difference in thrombus attenuation in MCA occlusions with an additional extracranial ICA occlusion compared with isolated MCA occlusions, a relevant threshold of thrombus attenuation was not found.

中文翻译：

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Hounsfield 装置在急性缺血性卒中串联闭塞诊断中的应用

 背景

串联闭塞可能会使医疗和血管内中风治疗复杂化。为了识别这些闭塞，计算机断层扫描血管造影 (CTA) 是最好的成像方式。然而，对于一些未直接入住卒中中心的患者，最初仍未进行 CTA。早期识别近端颅外颈内动脉的额外闭塞可能会改善最合适的治疗策略。本研究的目的是在非对比头部 CT (NCCT) 扫描中找到有价值的血栓衰减阈值，以促进串联闭塞的安全诊断。

 材料和方法

从我们的神经血管内干预登记中确定了连续接受血管内治疗的急性大脑中动脉（MCA）闭塞患者。通过 NCCT 测量受影响的 MCA 和对侧血管的血栓衰减。为了比较个体基线血液衰减，计算血栓衰减与对侧 MCA 衰减之间的差异（称为 ΔTM）。

 结果

其中包括三百二十五名患者。孤立性 MCA 闭塞和额外颅外颈内动脉 (ICA) 闭塞的平均血栓衰减之间存在高度显着差异（49.9 ± 8 与 56.2 ± 10 Hounsfield 单位 (HU)； P < 0.001）。 ΔTM 的受试者工作特征曲线下面积为 0.72。最佳阈值为13.5 HU，敏感性为67.5%，特异性为68.6%。

 结论

尽管与单独的 MCA 闭塞相比，附加颅外 ICA 闭塞的 MCA 闭塞中的血栓衰减存在显着差异，但尚未发现血栓衰减的相关阈值。