Integrated Multi-frequency Intravascular Ultrasound and Photoacoustic Imaging

集成多频血管内超声和光声成像

• 批准号: 435600-2013
• 负责人: Foster, Stuart
• 金额: $ 2.99万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=552818
• 关键词: Integrated; Multi; frequency; Intravascular; Ultrasound

The majority (50-60%) of sudden cardiac deaths are the result of acute intracoronary thrombosis arising from what are frequently referred to as vulnerable plaques. Angiography, the gold standard in interventional coronary artery lumen imaging, is well suited to identifying flow-limiting lesions but it is now recognized that a significant proportion of ensuing cardiac events resulting in fatalities arise from vulnerable plaques that do not have significant stenosis. There is therefore an intense interest in developing imaging methods to identify these lesions with the objective of improving guidance for interventional procedures (e.g. stent placements). Intravascular imaging has the potential to detect vulnerable plaque if methods can be devised to detect 1) the thin fibrous cap at the surface of these dangerous lesions and 2) the underlying thrombogenic lippid pools that are thought to play a major role in rupture and vessel blockage. We plan to create a catheter based imaging approach that is designed to detect and quantify both of these features. Our technical expertise in the areas of micro-ultrasound arrays, photoacoustics, and intravascular ultrasound (IVUS) transducers will be the basis for the new intravascular technologies proposed here. The specific objectives of this research are to: 1) develop a bidirectional 2 frequency catheter based ultrasound probe in which the transducer is optimized for detection of thin fibrous caps in the 60 to 100 MHz range, 2) combine the dual frequency IVUS probe with appropriate optical fibre technology for the delivery of pulsed or modulated continuous wave laser energy in the near infrared region of the spectrum to perform photoacoustic imaging of lipids, and 3) quantify ultrasound and laser beam distributions and perform studies of device performance in phantoms, ex vivo coronary artery samples, and in vivo in animal models. The novelty in this project is high in that multi-frequency IVUS catheters have not previously been integrated into intravascular imaging systems much less combined with photoacoustics. This new technology would thus be well positioned to guide interventions and assist in critical decision making regarding the risk associated with vulnerable plaque.

大多数（50-60%）心脏性猝死是由常被称为易损斑块的急性冠状动脉内血栓形成引起的。 血管造影术是介入性冠状动脉管腔成像的金标准，非常适合于识别限流性病变，但现在认识到，导致死亡的相当大比例的随后心脏事件来自不具有显著狭窄的易损斑块。 因此，人们对开发成像方法以识别这些病变具有强烈的兴趣，目的是改善介入手术（例如支架置入）的指导。 血管内成像具有检测易损斑块的潜力，如果可以设计方法来检测1）这些危险病变表面的薄纤维帽和2）被认为在破裂和血管阻塞中起主要作用的潜在血栓形成脂质池。 我们计划创建一种基于导管的成像方法，旨在检测和量化这两种功能。 我们在微超声阵列、光声和血管内超声（IVUS）换能器领域的技术专长将成为本文提出的新血管内技术的基础。这项研究的具体目标是：1）开发基于双向2频率导管的超声探头，其中换能器被优化用于在60至100 MHz范围内检测薄纤维帽，（二）联合收割机将双频IVUS探头与适当的光纤技术相结合，用于在光谱的近红外区域中输送脉冲或调制的连续波激光能量，进行脂质的光声成像，以及3）量化超声和激光束分布，并在体模、离体冠状动脉样本和动物模型中进行体内装置性能的研究。 该项目的新奇在于，多频IVUS导管以前没有集成到血管内成像系统中，更不用说与光声相结合。因此，这项新技术将能够很好地指导干预措施，并协助做出与易损斑块相关的风险的关键决策。