Nagesh S V Setlur, Bednarek D R, Rudin S
Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo NY, USA.
Proc SPIE Int Soc Opt Eng. 2021 Feb;11595. doi: 10.1117/12.2580866. Epub 2021 Feb 15.
X-ray guided neurointerventions are catheter-based treatments for cerebrovascular diseases such as strokes and aneurysms. During such procedures visualization of treatment devices is the primary imaging task. In this work we investigate the necessity of x-ray scatter-reduction grids in performing those tasks. Various endovascular treatment devices such as stents, coils and catheters along with a low contrast blood vessel phantom were placed on a head-equivalent phantom. Images of the objects were acquired with and without a grid (15:1 grid ratio, 80 lines/cm and Al interspace). The x-ray field was set to the full 8 x 8 inch FOV to allow for realistic scatter generation. The detector was positioned close to the phantom to investigate maximal scatter conditions. Contrast and Contrast to Noise (CNR) ratios of the catheter tip and the blood vessel phantom were measured and compared for images obtained with and without the grid. The x-ray technique parameters were kept constant for all acquisitions. For the catheter tip there was a 43% reduction in contrast with the removal of the grid due to increased scatter reaching the detector. However, due to increased primary there was a 18% increase in CNR. For the blood vessel phantom, there was a 33% reduction in contrast, whereas a 17% increase in CNR. All the devices and the blood vessels in the phantom were still visible even with the increased scatter without the grid. The results of the study indicate the use of grids during neurointervention procedures might not be necessary to perform the intervention.
X射线引导下的神经介入治疗是针对中风和动脉瘤等脑血管疾病的基于导管的治疗方法。在这些手术过程中，治疗设备的可视化是主要的成像任务。在这项工作中，我们研究了在执行这些任务时减少X射线散射格栅的必要性。将各种血管内治疗设备，如支架、线圈和导管，以及一个低对比度血管模型放置在一个头部等效模型上。在有和没有格栅（格栅比为15:1，80线/厘米，铝间隔）的情况下采集物体的图像。X射线场设置为完整的8×8英寸视野，以允许产生实际的散射。探测器靠近模型放置，以研究最大散射条件。测量并比较了有和没有格栅时获得的图像中导管尖端和血管模型的对比度和对比度噪声比（CNR）。所有采集的X射线技术参数保持不变。对于导管尖端，由于到达探测器的散射增加，去除格栅后对比度降低了43%。然而，由于原发射线增加，CNR增加了18%。对于血管模型，对比度降低了33%，而CNR增加了17%。即使在没有格栅的情况下散射增加，模型中的所有设备和血管仍然可见。研究结果表明，在神经介入手术过程中使用格栅可能不是进行介入治疗所必需的。
