光声成像,一个针对癌症的非侵入性诊断很有前途的技术Optoacoustic imaging, a promising technique for non-invasive diagnosis of cancer |
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课程网址: | http://videolectures.net/kolokviji_frenz_oipt/ |
主讲教师: | Martin Frenz |
开课单位: | 伯尔尼大学 |
开课时间: | 2008-07-05 |
课程语种: | 英语 |
中文简介: | 光学声学提供高光学对比度,而不妨碍光学混浊组织成像的低分辨率。在生物医学光学声学中,组织被短激光脉冲照射。光分散在组织内部,而吸热结构,如血管,则隐藏在组织内部深处。因此,图像对比度由吸光发色团提供,无论是内源性(如氧血红蛋白或脱氧血红蛋白)还是外源性(如染料、纳米颗粒或量子点)。由于热弹性效应,非均匀加热产生的压力瞬变恰好代表了吸收结构。这些声波瞬变传播到组织表面,可以用适当的超声波传感器检测到。在一维光声测量中,激光脉冲与被测压力瞬变之间的时间延迟、振幅和时间分布提供了声源位置、强度和空间尺寸的信息。通过扫描传感器可以重建三维图像。图像质量取决于许多因素,包括辐射几何和图像重建算法。本文将对混浊组织中光声成像的可能性和局限性进行综述,特别是在图像对比度和深度分辨率方面。 |
课程简介: | Optoacoustics provides high optical contrast without the handicap of poor resolution in imaging of optically turbid tissues. In biomedical optoacoustics, tissue is illuminated with short laser pulses. The light is scattered inside the tissue and heats absorbing structures, such as blood vessels, hidden deeply inside the tissue. Image contrast is therefore provided by light absorbing chromophores, either endogenous (such as oxy- or deoxyhemoglobin) or exogenous (e.g. dyes, nanoparticles or quantum dots). By means of the thermoelastic effect, the inhomogeneous heating generates pressure transients exactly representing the absorbing structures. These acoustic transients propagate to the tissue surface and can be detected with an appropriate ultrasound transducer. In one-dimensional optoacoustic measurements, time delay between the laser pulse and detected pressure transient, its amplitude and temporal profile provide information about the location, strength and spatial dimension of the acoustic source. Three-dimensional images can be reconstructed by scanning the transducer. The image quality depends on a number of factors, including the irradiation geometry and image reconstruction algorithm. The talk will give an overview of the possibilities and limitations of optoacoustic imaging in turbid tissues, especially in terms of image contrast and depth resolution. |
关 键 词: | 光学生物组织成像; 热弹性效应; 三维图像; 图像重建算法 |
课程来源: | 视频讲座网 |
最后编审: | 2019-12-24:lxf |
阅读次数: | 70 |