Department of Medical Physics, University of Wisconsin Madison, Madison, WI, USA.
Department of Radiology, School of Medicine and Public Health, University of Wisconsin, 600 Highland Ave, Madison, WI, 53792, USA.
Cardiovasc Intervent Radiol. 2024 Aug;47(8):1119-1126. doi: 10.1007/s00270-024-03809-7. Epub 2024 Jul 11.
Quantitative digital subtraction angiography (qDSA) has been proposed to quantify blood velocity for monitoring treatment progress during blood flow altering interventions. The method requires high frame rate imaging [~ 30 frame per second (fps)] to capture temporal dynamics. This work investigates performance of qDSA in low radiation dose acquisitions to facilitate clinical translation.
Velocity quantification accuracy was evaluated at five radiation dose rates in vitro and in vivo. Angiographic technique ranged from 30 fps digital subtraction angiography ( at the interventional reference point) down to a 30 fps protocol at 23% higher radiation dose per frame than fluoroscopy ( ). The in vitro setup consisted of a 3D-printed model of a swine hepatic arterial tree connected to a pulsatile displacement pump. Five different flow rates (3.5-8.8 mL/s) were investigated in vitro. Angiography-based fluid velocity measurements were compared across dose rates using ANOVA and Bland-Altman analysis. The experiment was then repeated in a swine study (n = 4).
Radiation dose rate reductions for the lowest dose protocol were 99% and 96% for the phantom and swine study, respectively. No significant difference was found between angiography-based velocity measurements at different dose rates in vitro or in vivo. Bland-Altman analysis found little bias for all lower-dose protocols (range: [- 0.1, 0.1] cm/s), with the widest limits of agreement ([- 3.3, 3.5] cm/s) occurring at the lowest dose protocol.
This study demonstrates the feasibility of quantitative blood velocity measurements from angiographic images acquired at reduced radiation dose rates.
定量数字减影血管造影（qDSA）已被提议用于量化血流改变干预期间的血流速度，以监测治疗进展。该方法需要高帧率成像[~30 帧/秒（fps）]来捕捉时间动态。这项工作研究了在低辐射剂量采集下 qDSA 的性能，以促进临床转化。
在体外和体内，评估了五种辐射剂量率下的速度量化准确性。血管造影技术范围从 30 fps 数字减影血管造影（在介入参考点）下降到 30 fps 协议，与荧光透视相比，每帧辐射剂量增加 23%（在介入参考点）。体外设置由连接到脉动位移泵的猪肝动脉树的 3D 打印模型组成。在体外研究了五个不同的流速（3.5-8.8 mL/s）。使用方差分析和 Bland-Altman 分析比较了不同剂量率下的基于血管造影的流体速度测量值。然后在猪研究中重复了该实验（n=4）。
最低剂量方案的辐射剂量率降低了 99%和 96%，分别用于体模和猪研究。在体外和体内，不同剂量率下的基于血管造影的速度测量值之间未发现显著差异。Bland-Altman 分析发现，所有低剂量方案的偏差都很小（范围：[-0.1，0.1]cm/s），最宽的一致性界限（[-3.3，3.5]cm/s）发生在最低剂量方案。
本研究证明了从低辐射剂量采集的血管造影图像中进行定量血流速度测量的可行性。
