Photoacoustic ultrasound: theory
Photoacoustic ultrasound: theory
复制标题
光声超声：理论
DOI：
--
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Pingyu Liu
中科院分区：
文献类型：
--
作者：
R. Kruger;Pingyu Liu
在生物组织内定位光学吸收受到在这种组织内发生的光的无处不在的散射的损害。作为纯光学检测方案的替代方案，通过检测每当在这种组织内发生辐射的差分吸收时产生的声波，可以检测光学辐射的区域吸收并将其定位在高度散射的组织内。当光辐射源以<1微秒ec持续时间的脉冲传递时，产生的声波位于医学超声频率范围内，并且可以使用常规超声换能器和重建方法来定位。这种声波的局部化不会受到光学散射的不利影响。本文介绍了混浊介质中声波产生的简化理论。建立了辐射光脉冲功率、区域吸收和声波产生强度之间的关系。假设使用传统的聚焦超声换能器和平移扫描，给出了对比度和空间分辨率的估计。初步的理论工作表明，光吸收可以定位与毫米空间分辨率为10%或更少的吸收，在生物组织厚为6.0厘米，使用安全水平的光辐射。
Localizing optical absorption within biologic tissue is compromised by the ubiquitous scattering of light that takes place within such tissues. As an alternative to purely optical detection schemes, regional absorption of optical radiation can be detected and localized within highly scattering tissues by detecting the acoustic waves that are produced whenever differential absorption of radiation takes place within such tissues. When the source of optical radiation is delivered in pulses of <EQ 1 microsecond(s) ec duration, the acoustic waves that are produced lie in the medical ultrasonic frequency range, and can be localized using conventional ultrasonic transducers and reconstruction methodology. Localizing such acoustic waves is not adversely affected by optical scattering. This paper introduces a simplistic theory of acoustic wave production within turbid media. The relationships among the irradiating optical pulse power, regional absorption, and strength of acoustic wave production are developed. Estimates of contrast and spatial resolution are presented, assuming a conventional, focused ultrasound transducer and translational scanning are used. Initial theoretical work indicates that optical absorption can be localized with millimeter spatial resolution for 10% absorption or less in biologic tissues as thick as 6.0 cm using safe levels of optical radiation.