Liebeskind David S, Kosinski Andrzej S, Saver Jeffrey L, Feldmann Edward
UCLA Stroke Center, Los Angeles, Calif., USA.
Duke University, Durham, N.C., USA.
Interv Neurol. 2014 Aug;2(4):153-9. doi: 10.1159/000360952.
The Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) study validated noninvasive imaging tests of intracranial atherosclerosis against catheter angiography in a prospective, blinded, multicenter setting. Critical evaluation of transcranial Doppler (TCD) and magnetic resonance angiography in the SONIA study standardized their performance and interpretation. We performed a similar analysis of computed tomography angiography (CTA) for the detection of intracranial stenosis.
Multicenter standardization of image acquisition and blinded, central interpretation of CTA performance were conducted in concert with the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial. Measurements of the intracranial arterial diameter were obtained to derive stenosis values. Correlation with catheter angiography was used to assess CTA performance characteristics.
CTA measurements of intracranial stenosis were obtained in 120 vessel segments, with angiographic correlation in 52. CTA was performed as a noninvasive study prior to conventional angiography. CTA stenoses of 50-99% or a flow gap were identified in 15 of 52 vessel segments, stenoses of <50% in 5 of 52, and normal arterial diameters in 32 of 52 vessel segments. Based on the digital subtraction angiography (DSA) stenosis defined as 50-99%, the positive predictive value (PPV) of CTA was only 46.7% (95% CI 21.3-73.4) and the negative predictive value (NPV) was 73.0% (95% CI 55.9-86.2). For DSA stenosis defined as 70-99%, the PPV of CTA was 13.3% (95% CI 1.7-40.5) and the NPV was 83.8% (95% CI 68.0-93.8).
CTA can accurately rule out the presence of severe stenosis due to intracranial atherosclerosis and may eliminate the need for angiography in many cases. Further prospective, blinded evaluation of CTA and optimization of cutpoints to predict angiographic disease will facilitate future trials of intracranial atherosclerosis.
颅内动脉粥样硬化的卒中结局与神经影像学（SONIA）研究在一项前瞻性、盲法、多中心研究中，将颅内动脉粥样硬化的无创成像检查与导管血管造影进行了对比验证。SONIA研究中对经颅多普勒（TCD）和磁共振血管造影的严格评估规范了它们的性能和解读。我们对计算机断层扫描血管造影（CTA）检测颅内狭窄进行了类似分析。
与华法林 - 阿司匹林有症状颅内疾病（WASID）试验协同进行了图像采集的多中心标准化以及CTA性能的盲法、集中解读。获取颅内动脉直径测量值以得出狭窄值。通过与导管血管造影的相关性来评估CTA的性能特征。
在120个血管节段进行了颅内狭窄的CTA测量，其中52个有血管造影相关性。CTA是在传统血管造影之前作为无创检查进行的。在52个血管节段中，15个发现CTA狭窄为50 - 99%或有血流间隙，5个狭窄小于50%，32个血管节段动脉直径正常。基于数字减影血管造影（DSA）将狭窄定义为50 - 99%，CTA的阳性预测值（PPV）仅为46.7%（95%可信区间21.3 - 73.4），阴性预测值（NPV）为73.0%（95%可信区间55.9 - 86.2）。对于DSA将狭窄定义为70 - 99%，CTA的PPV为13.3%（95%可信区间(1.7 - 40.5)），NPV为83.8%（95%可信区间68.0 - 93.8）。
CTA能够准确排除颅内动脉粥样硬化所致严重狭窄的存在，在许多情况下可能无需进行血管造影。对CTA进行进一步的前瞻性、盲法评估以及优化预测血管造影疾病的切点，将有助于未来颅内动脉粥样硬化的试验。
