Cunningham I A, Yamada S, Hobbs B B, Fenster A
Imaging Research Laboratories, John P. Robarts Research Institute, London, Ontario, Canada.
Med Phys. 1989 Mar-Apr;16(2):179-87. doi: 10.1118/1.596411.
An x-ray imaging system is described that can be used for obtaining arterial blood flow information. The system consists of a linear photodiode array image detector, simple optical and mechanical components, and a data acquisition microcomputer that connect to a conventional x-ray image intensifier based fluorography system. Flow information is obtained by detecting the movement of a small, locally injected bolus of radio-opaque contrast agent. This is done by determining the bolus mass, integrated over the cross-sectional area, at each of 1024 positions along the length of the artery with a sampling rate of up to 200 samples per s. It is shown in a phantom study that the peak flow velocity can be measured with an accuracy of +/- 5% by detecting the bolus arrival times at each of the 1024 positions. The mean velocity is obtained with similar accuracy using a cross-correlation technique and a modified form of the Stewart-Hamilton principle. In addition, it is shown that the separation and reattachment points resulting from flow separation near a stenosis can be determined from the bolus clearance times. The locations of these points are consistent with theoretical values for the cosine shaped symmetric 89% stenosis used in this study.
描述了一种可用于获取动脉血流信息的X射线成像系统。该系统由线性光电二极管阵列图像探测器、简单的光学和机械部件以及数据采集微型计算机组成，这些部件连接到基于传统X射线图像增强器的荧光造影系统。通过检测局部注射的一小团不透射线造影剂的运动来获取血流信息。这是通过以高达每秒200个样本的采样率，在沿动脉长度的1024个位置中的每个位置确定造影剂团块在横截面上的质量积分来实现的。在模型研究中表明，通过检测1024个位置中每个位置的造影剂团块到达时间，可以以±5%的精度测量峰值流速。使用互相关技术和改良形式的斯图尔特 - 哈密顿原理，以类似的精度获得平均流速。此外，还表明可以从造影剂清除时间确定狭窄附近血流分离产生的分离点和重新附着点。这些点的位置与本研究中使用的余弦形对称89%狭窄的理论值一致。
