Abstract：
BACKGROUND: Stroke is the second leading cause of death across the globe. Early screening and risk detection could provide early intervention and possibly prevent its incidence. Imaging modalities, including 1D-Transcranial Doppler Ultrasound (1D-TCD) or Transcranial Color-code sonography (TCCS), could only provide low spatial resolution or 2D image information, respectively. Notably, 3D imaging modalities including CT have high radiation exposure, whereas MRI is expensive and cannot be adopted in patients with implanted devices. This study proposes an alternative imaging solution for reconstructing 3D Doppler ultrasound geared towards providing a screening tool for the 3D vessel structure of the brain.
METHODS: The system comprises an ultrasound phased array attached to a servo motor, which can rotate 180˚ at a speed of 2˚/s. We extracted the color Doppler ROI from the image before reconstructing it into a 3D view using a customized pixel-based algorithm. Different vascular diameters, flow velocity, and depth were tested using a vascular phantom with a pumped flow to confirm the system for imaging blood flow. These variables were set to mimic the vessel diameter, flow speed, and depth of the Circle of Willis (CoW) during a transcranial screening.
CONCLUSIONS: The lower values of absolute error and ratio were found in the larger vascular channels, and vessel diameter overrepresentation was observed. Under different flow velocities, such diameter overrepresentation in the reconstructed flow did not change much; however, it did change with different depths. Meanwhile, the setting of the velocity scale and the color gain affected the dimension of reconstructed objectives. Moreover, we presented a 3D image of CoW from a subject to demonstrate its potential. The findings of this work can provide a good reference for further studies on the reconstruction of the CoW or other blood vessels using Doppler imaging.
METHODS: The system comprises an ultrasound phased array attached to a servo motor, which can rotate 180˚ at a speed of 2˚/s. We extracted the color Doppler ROI from the image before reconstructing it into a 3D view using a customized pixel-based algorithm. Different vascular diameters, flow velocity, and depth were tested using a vascular phantom with a pumped flow to confirm the system for imaging blood flow. These variables were set to mimic the vessel diameter, flow speed, and depth of the Circle of Willis (CoW) during a transcranial screening.
CONCLUSIONS: The lower values of absolute error and ratio were found in the larger vascular channels, and vessel diameter overrepresentation was observed. Under different flow velocities, such diameter overrepresentation in the reconstructed flow did not change much; however, it did change with different depths. Meanwhile, the setting of the velocity scale and the color gain affected the dimension of reconstructed objectives. Moreover, we presented a 3D image of CoW from a subject to demonstrate its potential. The findings of this work can provide a good reference for further studies on the reconstruction of the CoW or other blood vessels using Doppler imaging.
摘要：
背景：中风是全球第二大死亡原因。早期筛查和风险检测可以提供早期干预，并可能预防其发生。成像模式，包括1D-经颅多普勒超声（1D-TCD）或经颅色码超声（TCCS），只能提供低空间分辨率或2D图像信息，分别。值得注意的是,包括CT在内的3D成像模式具有高辐射暴露，而MRI价格昂贵，无法在植入设备的患者中采用。这项研究提出了一种用于重建3D多普勒超声的替代成像解决方案，旨在为大脑的3D血管结构提供筛查工具。
方法：该系统包括连接到伺服电机的超声相控阵，可以以2º/s的速度旋转180º。我们从图像中提取彩色多普勒ROI，然后使用定制的基于像素的算法将其重建为3D视图。不同的血管直径，流速,和深度使用带有泵送流量的血管体模进行测试，以确认用于成像血流的系统。这些变量设置为模拟血管直径，流速,经颅筛查时威利斯环(CoW)的深度。
结论：在较大的血管通道中发现绝对误差和比值较低，观察到血管直径过高。在不同的流速下，重建流中的这种直径过度表示没有太大变化；然而，它确实随着不同的深度而变化。同时,速度标度和颜色增益的设置影响重建目标的尺寸。此外，我们展示了一个受试者的CoW的3D图像，以证明其潜力。这项工作的发现可以为进一步研究使用多普勒成像重建CoW或其他血管提供很好的参考。
方法：该系统包括连接到伺服电机的超声相控阵，可以以2º/s的速度旋转180º。我们从图像中提取彩色多普勒ROI，然后使用定制的基于像素的算法将其重建为3D视图。不同的血管直径，流速,和深度使用带有泵送流量的血管体模进行测试，以确认用于成像血流的系统。这些变量设置为模拟血管直径，流速,经颅筛查时威利斯环(CoW)的深度。
结论：在较大的血管通道中发现绝对误差和比值较低，观察到血管直径过高。在不同的流速下，重建流中的这种直径过度表示没有太大变化；然而，它确实随着不同的深度而变化。同时,速度标度和颜色增益的设置影响重建目标的尺寸。此外，我们展示了一个受试者的CoW的3D图像，以证明其潜力。这项工作的发现可以为进一步研究使用多普勒成像重建CoW或其他血管提供很好的参考。
