Optical Tomography Using Change of Ultrasonic Velocity by Light Absorption in Tissue

利用组织中光吸收改变超声波速度的光学断层扫描

• 批准号: 12555014
• 负责人: HORINAKA Hiromichi
• 金额: $ 3.97万
• 依托单位: Osaka Prefecture University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12555014/
• 关键词: optical computed tomography; acousto-optic effect; ultrasonic velocity; ultrasonic phase; metabolic information; tissue; scattering medium; diagnostics; 超音波; 光断層画像; 光吸収; 光散乱; 音速; 分光特性

The optical CT is particulary expected to be applied to measurement of distribution of oxyhemoglobin in the brain and spatial diagnosis of tumors. However it is difficult to reconstruct the optical tomography because a biological tissue is highly scattering medium for light. A method using ultrasonic velocity change due to light absorption was proposed to realize practical optical computed tomography.The experimental setup for detecting the ultrasonic phase shift caused by the optical absorption was constructed. Two transducers were placed face to face in a transparent acryl container as a transmitter and a receiver. When light illuminates the scattering medium containing absorption objects, the temperature of the absorption area increases and the phase of ultrasonic wave propagating the area shifts. The phase and the amplitude of the receiver output are measured using the RF lock-in amplifier. The difference between the ultrasonic phase under light illumination and that in the dark is determined and is stored in a personal computer. As the measured value is phase-shift integrated along the propagation path of ultrasonic wave, the ultrasonic wave must be scanned around the sample in order to reconstruct the optical tomography image.The phase shift of ultrasonic wave was observed even in the medium with a scattering coefficient equivalent to that of the human brain when ultrasonic wave passed through absorption objects under light illumination. The optical image of the absorption region in a scattering medium was reconstructed from the projection data of ultrasonic phase shift due to light illumination. The shape of the absorption object hidden in the chicken meat was recognized by detecting the ultrasonic phase shift due to light illumination.

光学CT尤其有望应用于脑内氧合血红蛋白分布的测量和肿瘤的空间诊断。然而，由于生物组织是光的高度散射介质，因此很难重建光学断层扫描。提出了一种利用光吸收引起的超声速度变化的方法来实现实用的光学计算机断层扫描。搭建了检测光吸收引起的超声相移的实验装置。两个传感器面对面放置在透明亚克力容器中作为发射器和接收器。当光照射包含吸收物体的散射介质时，吸收区域的温度升高并且传播该区域的超声波的相位发生变化。使用射频锁定放大器测量接收器输出的相位和幅度。确定光照下和黑暗下的超声波相位之间的差异并将其存储在个人计算机中。由于测量值是沿着超声波传播路径进行相移积分，因此超声波必须在样品周围扫描才能重建光学断层图像。即使在具有散射的介质中也可以观察到超声波的相移。相当于超声波在光照射下通过吸收物体时人脑的系数。散射介质中吸收区域的光学图像是根据光照射引起的超声相移的投影数据重建的。通过检测光照射引起的超声波相移来识别隐藏在鸡肉中的吸收物体的形状。

项目成果

H.Horinaka, K.Wada, A.Okasaka, Y.Cho, T.Matsunaka, S.Syouhei: "Optical computed tomography imaging of absorbers hidden in scattering medium by detection of ultrasonic phase-shift caused by laser illumination-Ultrasonic Velocity Imaging"Proceedings of 2000

H.Horinaka、K.Wada、A.Okasaka、Y.Cho、T.Matsunaka、S.Syouhei：“通过检测激光照射引起的超声波相移，对隐藏在散射介质中的吸收体进行光学计算机断层扫描成像 - 超声波速度成像

H. Horinaka: "Optical Tomography Image Using Ultrasonic Phase-Shift Due to Light Absorption"Journal of the Japan Society for Precision Engineering. Vol.67, No.4. 554-557 (2001)

H. Horinaka：“利用光吸收引起的超声波相移的光学断层扫描图像”日本精密工程学会期刊。

H. Horinaka, T. Matsunaka,T. Iwade, T. Masumura, T. Kobayashi, T. Kiuchi, K.Wada and Y. Cho: "Optical Imaging in Scattering Medium by Detection of Ultrasonic Phase-Shift Due to Light Illumination"Jpn. J. Appl. Phys. Accepted for publication Feb. 06. (to b

H.堀中，T.松中，T.

T. Kiuchi, A. Okasaka, T. Kobayashi, H. Horinaka, K. Wada, Y. Cho,T. Matsunaka and S. Saimi: Tech. Dig. of The Pacific Rim Conf. on Lasers and Electro-Optics. Vol.II. 306-307 (2001)

T. Kiuchi、A. Okasaka、T. Kobayashi、H. Horinaka、K. Wada、Y. Cho、T.

H.Horinaka, T.Matsunaka, T.Iwade, T.Masumura, T.Kobayashi, T.Kiuchi, K.Wada, Y.Cho: "Optical Imaging in Scattering Medium by Detection of Ultrasonic Phase-Shift Due to Light Illumination"Jpn. J. Appi. Phys.. Vol.41,No.5(Regular paper)掲載決定. (2002)

H.Horinaka、T.Matsunaka、T.Iwade、T.Masumura、T.Kobayashi、T.Kiuchi、K.Wada、Y.Cho：“通过检测光照明引起的超声波相移来实现散射介质中的光学成像” Jpn. J. Appi. 第 41 卷，第 5 号（普通论文）出版决定（2002 年）。