Feldmann E, Wilterdink J L, Kosinski A, Lynn M, Chimowitz M I, Sarafin J, Smith H H, Nichols F, Rogg J, Cloft H J, Wechsler L, Saver J, Levine S R, Tegeler C, Adams R, Sloan M
Department of Clinical Neurosciences, Brown University School of Medicine, Providence, RI 02903, USA.
Neurology. 2007 Jun 12;68(24):2099-106. doi: 10.1212/01.wnl.0000261488.05906.c1. Epub 2007 Apr 4.
Transcranial Doppler ultrasound (TCD) and magnetic resonance angiography (MRA) can identify intracranial atherosclerosis but have not been rigorously validated against the gold standard, catheter angiography. The WASID trial (Warfarin Aspirin Symptomatic Intracranial Disease) required performance of angiography to verify the presence of intracranial stenosis, allowing for prospective evaluation of TCD and MRA. The aims of Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) trial were to define abnormalities on TCD/MRA to see how well they identify 50 to 99% intracranial stenosis of large proximal arteries on catheter angiography.
SONIA standardized the performance and interpretation of TCD, MRA, and angiography. Study-wide cutpoints defining positive TCD/MRA were used. Hard copy TCD/MRA were centrally read, blind to the results of angiography.
SONIA enrolled 407 patients at 46 sites in the United States. For prospectively tested noninvasive test cutpoints, positive predictive values (PPVs) and negative predictive values (NPVs) were TCD, PPV 36% (95% CI: 27 to 46); NPV, 86% (95% CI: 81 to 89); MRA, PPV 59% (95% CI: 54 to 65); NPV, 91% (95% CI: 89 to 93). For cutpoints modified to maximize PPV, they were TCD, PPV 50% (95% CI: 36 to 64), NPV 85% (95% CI: 81 to 88); MRA PPV 66% (95% CI: 58 to 73), NPV 87% (95% CI: 85 to 89). For each test, a characteristic performance curve showing how the predictive values vary with a changing test cutpoint was obtained.
Both transcranial Doppler ultrasound and magnetic resonance angiography noninvasively identify 50 to 99% intracranial large vessel stenoses with substantial negative predictive value. The Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis trial methods allow transcranial Doppler ultrasound and magnetic resonance angiography to reliably exclude the presence of intracranial stenosis. Abnormal findings on transcranial Doppler ultrasound or magnetic resonance angiography require a confirmatory test such as angiography to reliably identify stenosis.
经颅多普勒超声（TCD）和磁共振血管造影（MRA）能够识别颅内动脉粥样硬化，但尚未与金标准——导管血管造影进行严格验证。华法林阿司匹林治疗有症状颅内疾病（WASID）试验要求进行血管造影以证实颅内狭窄的存在，从而能够对TCD和MRA进行前瞻性评估。颅内动脉粥样硬化的卒中结局与神经影像学（SONIA）试验的目的是确定TCD/MRA上的异常情况，以了解它们在导管血管造影中识别大脑近端大动脉50%至99%颅内狭窄的准确性。
SONIA对TCD、MRA和血管造影的操作及解读进行了标准化。采用了全研究范围的定义TCD/MRA阳性的切点。TCD/MRA的硬拷贝图像由中心阅片，阅片者对血管造影结果不知情。
SONIA在美国46个地点招募了407名患者。对于前瞻性测试的无创检查切点，阳性预测值（PPV）和阴性预测值（NPV）分别为：TCD，PPV 36%（95%置信区间：27%至46%）；NPV，86%（95%置信区间：81%至89%）；MRA，PPV 59%（95%置信区间：54%至65%）；NPV，91%（95%置信区间：89%至93%）。对于为最大化PPV而修改的切点，分别为：TCD，PPV 50%（95%置信区间：36%至64%），NPV 85%（95%置信区间：81%至88%）；MRA，PPV 66%（95%置信区间：58%至73%），NPV 87%（95%置信区间：85%至89%）。对于每项检查，均获得了一条特征性的性能曲线，显示预测值如何随检查切点的变化而变化。
经颅多普勒超声和磁共振血管造影均可无创识别50%至99%的颅内大血管狭窄，且具有较高的阴性预测值。颅内动脉粥样硬化的卒中结局与神经影像学试验方法使经颅多普勒超声和磁共振血管造影能够可靠地排除颅内狭窄的存在。经颅多普勒超声或磁共振血管造影的异常发现需要通过血管造影等确证检查来可靠地识别狭窄。
