Realization of the Low Frequency Transmission Beam Computed Tomography for the Abdominal Tissue Sound Speed Imaging

腹部组织声速成像低频透射束计算机断层扫描的实现

• 批准号: 15560357
• 负责人: YAMADA Akira
• 金额: $ 2.37万
• 依托单位: National University Corporation Tokyo University of Agriculture and Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560357/
• 关键词: Ultrasonic computed tomography; Acoustic inverse scattering; Ultrasonic transmission tomography; Image reconstruction; Diffraction tomography; Tissue quantitative image; Abdominal ultrasonic image; Medical ultrasonic diagnosis; 組織定量映像

Ultrasound travel time tomography for the quantitative sound speed image of the human abdominal tissue medium has been investigated. The realization of the present technique becomes difficult due to the large sound wave attenuation when transmitting the wave within an internal organ. In addition, existence of the spinal cord violates the weak scattering assumption assumed in the reconstruction of the image. To encounter the problems, low frequency transmission tomography was introduced to decrease the attenuation of the sound wave. Here, travel time along the path between the transmitter and receiver was assumed to be path integration of the inverse sound speed distributions. By this means, the image can be reconstructed from the data whose information is confined along the ray paths, as a result, the signal from the spinal cord can be excluded. As a means to reconstruct the image with small number of observation path data as well as excluding the spinal cord region, smoothed path algebraic reconstruction technique (SPART) was proposed. The validity of the method was demonstrated through the numerical simulation examination. It was also demonstrated that travel time of the transmitted waves by the narrow apertured transducers on the human body surface met well with the straight ray propagation model. Finally, it was shown that the rough estimate of the sound speed image could be obtained by using only 16 transducer elements and their combination of 120 small number of path data.

研究了超声走时层析成像对人体腹部组织介质的定量声速成像。由于当在内部器官内传输波时大的声波衰减，本技术的实现变得困难。另外，脊髓的存在违反了在图像重建中假设的弱散射假设。为了解决这一问题，人们引入了低频透射层析成像技术来减小声波的衰减。在这里，传播时间沿着之间的发送器和接收器的路径被假定为路径积分的反向声速分布。通过这种方法，可以从其信息被限制在沿着射线路径的数据中重建图像，从而可以排除来自脊髓的信号。平滑路径代数重建技术（SPART）是一种在不包含脊髓区域的情况下，利用少量观测路径数据重建图像的方法。通过数值仿真验证了该方法的有效性。研究还表明，窄孔径换能器在人体表面的传播时间与直线传播模型吻合得很好。最后表明，仅使用16个换能器元件及其120个少量路径数据的组合即可获得声速图像的粗略估计。

项目成果

Ultrasound Inverse Scattering CT Under the Angular Illumination Limitation

角照明限制下的超声逆散射CT

• 发表时间: 2004
• 期刊: Jpn.J.Appl.Phys. 43・8A
• 作者: A.Yamada;S.Yano
• 通讯作者: S.Yano

Ultrasound Inverse Scattering CT Under the Extremely Limited Angular Illuminations From Four Principal Orthogonal Directions

四个主正交方向极有限角照明下的超声逆散射CT

• 发表时间: 2004
• 期刊: The 18th International Congress on Acoustics ICA 2004
• 作者: J.S.Kim;J.H..Kim;A.Yamada;K.L.Ha;M.J.Kim;Akira Yamada
• 通讯作者: Akira Yamada

照射角制限性能の高い透過型超音波逆散乱CT

高照射角限制性能的透射式超声逆散射CT

• 发表时间: 2005
• 期刊: 超音波TECHNO 7・1
• 作者: 山田 晃

J.S.Kim, J.H.Kim, A.Yamada, K.L.Ha, M.J.Kim: "Array Ultrasonic Transducers on Arc Surface for Plane Wave Synthesis"Jpn.J.Appl.Phys.. (accepted for publication). (2004)

J.S.Kim、J.H.Kim、A.Yamada、K.L.Ha、M.J.Kim：“用于平面波合成的弧形表面上的阵列超声波换能器”Jpn.J.Appl.Phys..（已接受发表）。

A.Yamada, K.Nagao: "Nonlinear Focused Sound Field Measurement Using Laser Doppler Technique"The 18th International Congress on Acoustics. ICA 2004. II 1637-II 1638 (2004)

A.Yamada、K.Nagao：“使用激光多普勒技术进行非线性聚焦声场测量”第 18 届国际声学大会。