Shields A, Bhurwani M M S, Williams K, Chivukula V, Bednarek D R, Rudin S, Ionita C N
Canon Stroke and Vascular Research Center, University at Buffalo (SUNY), Buffalo, NY.
QAS.AI Inc, Buffalo, NY.
Proc SPIE Int Soc Opt Eng. 2023 Feb;12463. doi: 10.1117/12.2653119. Epub 2023 Apr 7.
Quantitative angiography (QAngio) may provide hemodynamic information during neurointerventional procedures through imaging biomarkers related to contrast flow. The standard clinical implementation of QAngio is limited by projection imaging: analysis of contrast motion within complex 3D geometries is restricted to 1-2 projection views, truncating the potential wealth of imaging biomarkers related to disease progression or efficacy of treatment. To understand the limitations of 2D biomarkers, we propose the use of in-silico contrast distributions to investigate the potential benefits of 3D-QAngio within the context of neurovascular hemodynamics. Ground-truth in-silico contrast distributions were generated in two patient-specific intracranial aneurysm models, accounting for the physical interactions of contrast media and blood. A short bolus of contrast was utilized to obtain full a wash-in/ wash-out cycle within the aneurysm ROI. Simulated angiograms mimicking clinical cone-beam CT (CBCT) acquisitions were then generated, and volumetric contrast distributions were reconstructed to analyze bulk contrast flow. The ground-truth 3D-CFD, reconstructed 3D-CBCT-DSA, and 2D-DSA projections were used to extract QAngio parameters related to contrast time dilution curves, such as area under the curve (AUC), peak height (PH), mean-transit-time (MTT), time-to-peak (TTP), and time to arrival (TTA). An initial comparison of quantitative flow parameters in both 2D and 3D, in a smaller and larger aneurysm, indicated that 3D-QAngio can provide a good description of bulk flow characteristics (TTA, TTP, MTT), but recovery of integral parameters (PH, AUC) aneurysms is limited. Nonetheless, incorporation of 3D-QAngio methods may provide additional insight into our understanding of abnormal vascular flow patterns.
定量血管造影术（QAngio）可在神经介入手术过程中，通过与造影剂流动相关的成像生物标志物提供血流动力学信息。QAngio的标准临床应用受投影成像限制：对复杂三维几何结构内造影剂运动的分析仅限于1 - 2个投影视图，从而截断了与疾病进展或治疗效果相关的潜在丰富成像生物标志物。为了解二维生物标志物的局限性，我们提议使用计算机模拟造影剂分布，在神经血管血流动力学背景下研究三维QAngio的潜在益处。在两个患者特异性颅内动脉瘤模型中生成了真实的计算机模拟造影剂分布，考虑了造影剂与血液的物理相互作用。使用短剂量造影剂在动脉瘤感兴趣区内获得完整的注入/洗脱周期。然后生成模拟血管造影图，模拟临床锥形束CT（CBCT）采集，并重建体积造影剂分布以分析整体造影剂流动。利用真实的三维计算流体动力学（3D - CFD）、重建的三维CBCT - DSA和二维DSA投影来提取与造影剂时间稀释曲线相关的QAngio参数，如曲线下面积（AUC）、峰值高度（PH）、平均通过时间（MTT）、达峰时间（TTP）和到达时间（TTA）。在大小不同的动脉瘤中对二维和三维定量血流参数进行的初步比较表明，三维QAngio可以很好地描述整体血流特征（TTA、TTP、MTT），但对动脉瘤积分参数（PH、AUC）的恢复有限。尽管如此，纳入三维QAngio方法可能会为我们理解异常血管血流模式提供更多见解。
