Frontiers of Photoacoustic Imaging

光声成像的前沿

• 批准号: 355544-2013
• 负责人: Zemp, Roger
• 金额: $ 2.11万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=636954
• 关键词: Frontiers; Photoacoustic; Imaging

The long-term objective of our proposed research is to develop photoacoustic imaging technologies that push new frontiers of biomedical imaging. Photoacoustic imaging is an emerging biomedical imaging modality that uses pulsed lasers to excite tissues. When light is absorbed, sound waves are created and used to form images of the optical properties inside the body. We have made considerable progress photoacoustic imaging, however, we perceive some areas where PA imaging needs further development: (1) Aside from blood & melanin-based pigment, until recently little has been done to explore other naturally-occuring contrast mechanisms in the body. We propose a number of techniques to image into tissues to attain information about specific chemical bonds without the need for contrast agents. The proposed methods will also provide information about the time chemical species are in an excited state after being interrogated by a laser pulse. (2) Quantitation has been difficult in photoacoustic imaging. Ideally we would like to create quantitative images of optical absorption, scattering coefficients (important because cell nuclei are often enlarged in cancers and pre-cancers, affecting scattering), and concentrations of chromophores. A large number of methods have been proposed to algorithmically solve this non-trivial inverse problem, however, each has its own set of problems. More work is needed to develop a useful & robust method for improved quantitation and we propose key algorithms and methods to do this. (3) Improved ultrasound transducer technology is needed. Photoacoustic signals can be weak & sensitivity and frequency response should be maximized. Ultrabroadband & ultrasensitive transducers are proposed to improve the quality, resolution, and penetration depth of photoacoustic imaging. Our proposed research aims to address present limitations to bring PA imaging to new frontiers.

我们提出的研究的长期目标是开发光声成像技术，推动生物医学成像的新前沿。光声成像是一种新兴的生物医学成像方式，它使用脉冲激光来激发组织。当光被吸收时，就会产生声波，并用来形成人体内光学特性的图像。我们已经取得了相当大的进展，然而，我们认为PA成像需要进一步发展的领域：(1)除了基于血液和黑色素的色素外，直到最近，还很少有人研究身体内其他自然发生的对比机制。我们提出了一些技术来成像到组织中，以获得关于特定化学键的信息，而不需要造影剂。所提出的方法还将提供有关化学物质在被激光脉冲询问后处于激发状态的时间的信息。(2)定量一直是光声成像的难点。理想情况下，我们希望创建光吸收、散射系数(重要的是因为在癌症和癌前病变中细胞核经常增大，影响散射)和发色团浓度的定量图像。已经提出了大量的方法来用算法来解决这个非平凡的逆问题，然而，每一种方法都有自己的一组问题。我们还需要做更多的工作来开发一种有用的、健壮的方法来改进定量，我们提出了实现这一点的关键算法和方法。(3)超声换能器技术有待改进。光声信号可能很弱，应尽量提高灵敏度和频率响应。为了提高光声成像的质量、分辨率和穿透深度，人们提出了超宽带和超灵敏换能器。我们提出的研究旨在解决目前的局限性，将PA成像带入新的前沿。