Ultrasound Signal Processing for Quantitative Microvascular Imaging

这项发现基金将支持我们的研究开发改进的方法，使用超声波来成像小血管网络中的血流。这项研究很重要，因为目前的医学成像技术在测量血液流动的细微变化方面还不够有效，而血液流动的细微变化可能是癌症、心血管疾病和糖尿病等疾病治疗是否有效的最早证据。*我们的研究将改进用于血管成像的三种重要超声技术，即功率多普勒、超快成像和对比增强超声。功率多普勒是一种廉价的、广泛可用的血管网络成像技术，但图像受到超声系统操作员选择的设置的强烈影响。我们的创新之处在于能够自动选择其中一些设置，这将提高不同患者的图像之间或不同日期获得的单个患者图像之间比较的准确性。超快成像是一种最先进的多普勒成像方法，通过允许使用更多的测量来产生每张图像，可以改善对最小血管的成像。我们的实验室正在开发一种新的超快技术，名为“扩频多普勒”，它将在不降低图像质量的情况下，最大限度地增加血液流量测量的次数。我们还计划将扩频多普勒与我们选择扫描仪设置的自动化方法相结合，这将提高两种技术的有效性。对比增强超声利用微小的气泡来增加小血管的信号强度，使其超过多普勒可能达到的水平。我们的实验室正在开发新的方法来统计分析对比增强超声图像，目的是提高该技术对血管网络组织好坏变化的敏感性，这是获得癌症肿瘤和其他病变组织中血管网络的宝贵信息。我们的工作也有望对血管网络结构和这些血管的超声图像中包含的信息之间的物理关系产生新的见解，这将对其他医学成像研究人员有价值。本研究将为生物医学工程、电子工程和医学物理学的本科生和研究生提供培训机会，帮助这些学生为设计和开发医疗设备的工业或学术生涯做好准备。

This Discovery Grant will support our research developing improved methods to use ultrasound to image blood flow in networks of small vessels. This research is important because current medical imaging technologies are not sufficiently effective for measuring the subtle changes in blood flow that can be the earliest evidence that a patient is or is not being helped by treatments for conditions such as cancer, cardiovascular disease, and diabetes.* Our research will improve three important ultrasound technologies used for vascular imaging, namely power Doppler, ultrafast imaging, and contrast-enhanced ultrasound. Power Doppler is an inexpensive, widely available technology for imaging vessel networks, but the images are strongly affected by settings chosen by the operator of the ultrasound system. Our innovation is to automate the selection of some of those settings, which will improve the accuracy of comparisons among images of different patients or among images of an individual patient that are acquired on different days. Ultrafast imaging is a state-of-the-art Doppler method that improves imaging of the smallest vessels by allowing more measurements to be used to produce each image. Our lab is developing a new ultrafast technique named "spread-spectrum Doppler" that will maximize the number of blood-flow measurements made without reducing image quality. We also plan to combine spread-spectrum Doppler with our automated method for choosing scanner settings, which should increase the effectiveness of both techniques. Contrast-enhanced ultrasound uses microscopic bubbles to increase the signal strength from small vessels above the levels that are possible with Doppler. Our lab is developing new methods to statistically analyze contrast-enhanced ultrasound images with the goal of increasing the technique's sensitivity to changes in how well organized or disorganized a vessel network is, which is valuable information to obtain about vessel networks in cancer tumours and other diseased tissues. Our work is also expected to yield new insights into the physical relationships between the structure of blood vessel networks and the information contained in ultrasound images of those vessels that will be valuable to other medical imaging researchers. This research will provide training opportunities for undergraduate and graduate students in biomedical engineering, electrical engineering, and medical physics that will help prepare those students for industry or academic careers designing and developing medical devices.