Ultrasound Transmission Beam Computed Tomography for the In-situ Sound Speed Quantitative Diagnostic Imaging of Abdominal Tissue

研究了利用体表透射走时数据进行腹部声速层析成像的方法。为此，使用了100 kHz范围的低频波来减少波在内体介质中的衰减。研究了一种以尽可能少的路径数据重构腹部表面图像的方法。具体地说，应该避免来自强散射脊髓的数据。为了满足这一要求，引入了光滑路径代数重构技术。通过模拟合成数据和实验测量数据验证了该方法的有效性。结果表明，仅在腹壁周围准备32个传感器位置及其少于100个观测路径数据的组合，并避免数据与脊髓相交，即可成功获得腹部层析声速图像。此外，以低于阈值的声音速度提取脂肪区域，证明了该方法诊断代谢综合征的可能性。

Abdominal sound speed tomographic imaging using through-transmission travel time data on the body surface was investigated. To this end, a hundred kHz range low-frequency wave was used to reduce the wave attenuation within an inner body medium. A method was investigated for the reconstruction of the image with the smallest possible number of path data around the abdominal surface. Specifically, the data from a strong scattering spinal cord should be avoided. To fulfill the requirement, the smoothed path algebraic reconstruction technique was introduced. The validity of this method was examined both on the numerically synthesized data and the experimentally measured data for the phantom specimen and actual human subject. It was shown that an abdominal tomographic sound speed image could be successfully obtained by preparing only 32 transducer locations at the circumference around the abdominal surface and their combination of less than 100 number of observation path data as well as by avoiding the data intersecting the spinal cord. In addition, fat regions were extracted having a sound speed lower than the threshold value to demonstrate the possibility of this method for metabolic syndrome diagnosis.