Pereira V Mendes, Ouared R, Brina O, Bonnefous O, Satwiaski J, Aerts H, Ruijters D, van Nijnatten F, Perren F, Bijlenga P, Schaller K, Lovblad K-O
Interventional Neuroradiology Unit.
AJNR Am J Neuroradiol. 2014 Jan;35(1):156-63. doi: 10.3174/ajnr.A3662. Epub 2013 Aug 8.
Digital subtraction angiography is the reference standard technique to evaluate intracranial vascular anatomy and used on the endovascular treatment of vascular diseases. A dedicated optical flow-based algorithm was applied to DSA to measure arterial flow. The first quantification results of internal carotid artery flow validated with Doppler sonography are reported.
We included 22 consecutive patients who underwent endovascular procedures. To assess the sensitivity of the algorithm to contrast agent-blood mixing dynamics, we acquired high-frame DSA series (60 images/s) with different injection rates: 1.5 mL/s (n = 19), 2.0 mL/s (n = 18), and 3.0 mL/s (n = 13). 3D rotational angiography was used to extract the centerline of the vessel and the arterial section necessary for volume flow calculation. Optical flow was used to measure flow velocities in straight parts of the ICAs; these data were further compared with Doppler sonography data. DSA mean flow rates were linearly regressed on Doppler sonography measurements, and regression slope coefficient bias from value 1 was analyzed within the 95% confidence interval.
DSA mean flow rates measured with the optical flow approach significantly matched Doppler sonography measurements (slope regression coefficient, b = 0.83 ± 0.19, P = .05) for injection rate = 2.0 mL/s and circulating volumetric blood flow <6 mL/s. For injection rate = 1.5 mL/s, volumetric blood flow <3 mL/s correlated well with Doppler sonography (b = 0.67 ± 0.33, P = .05). Injection rate = 3.0 mL/s failed to provide DSA-optical flow measurements correlating with Doppler sonography because of the lack of measurable pulsatility.
A new model-free optical flow technique was tested reliably on the ICA. DSA-based blood flow velocity measurements were essentially validated with Doppler sonography whenever the conditions of measurable pulsatility were achieved (injection rates = 1.5 and 2.0 mL/s).
数字减影血管造影术是评估颅内血管解剖结构的参考标准技术，用于血管疾病的血管内治疗。一种基于光流的专用算法被应用于数字减影血管造影术以测量动脉血流。本文报告了经多普勒超声验证的颈内动脉血流的首次定量结果。
我们纳入了22例连续接受血管内手术的患者。为评估该算法对造影剂 - 血液混合动力学的敏感性，我们以不同注射速率（1.5 mL/s，n = 19；2.0 mL/s，n = 18；3.0 mL/s，n = 13）采集了高帧率数字减影血管造影术系列图像（60帧/秒）。使用三维旋转血管造影术提取血管中心线和计算体积血流所需的动脉段。利用光流测量颈内动脉直线段的血流速度；这些数据进一步与多普勒超声数据进行比较。数字减影血管造影术的平均血流速率与多普勒超声测量值进行线性回归，并在95%置信区间内分析回归斜率系数与1值的偏差。
对于注射速率 = 2.0 mL/s且循环体积血流量<6 mL/s，用光流法测量的数字减影血管造影术平均血流速率与多普勒超声测量值显著匹配（斜率回归系数，b = 0.83 ± 0.19，P = 0.05）。对于注射速率 = 1.5 mL/s，体积血流量<3 mL/s与多普勒超声相关性良好（b = 0.67 ± 0.33，P = 0.05）。由于缺乏可测量的搏动性，注射速率 = 3.0 mL/s未能提供与多普勒超声相关的数字减影血管造影术 - 光流测量结果。
一种新的无模型光流技术在颈内动脉上得到了可靠测试。只要达到可测量搏动性的条件（注射速率 = 1.5和2.0 mL/s），基于数字减影血管造影术的血流速度测量基本可通过多普勒超声验证。
