Novel Image Optimization Method for Joint Photoacoustic Tomography

The distribution of speed of sound （SOS） in biomedical tissue and delay compensation （DC） have significant impact on the image quality of photoacoustic tomography （PAT）. When imaging human peripheral joints, using fixed SOS and DC can only ensure that the reconstructed images are focused in a limited depth range, whereas they are defoeused at other depths, which cause severe artifacts and blurring. In this work, a linear-DC based reconstruction approach is proposed to focus the whole PAT image region. It is proved by two in vivo experiments that, compared with traditional delay-and-sum back projection algorithms, the proposed method can effectively optimize the image quality of articular tissues in PAT.     

Adaptive optimization on ultrasonic transmission tomography-based temperature image for biomedical treatment

Hyperthermia has proven to be beneficial to treating superficial malignancies, particularly chest wall recurrences of breast cancer. During hyperthermia, monitoring the time–temperature profiles in the target and surrounding areas is of great significance for the effect of therapy. An ultrasound-based temperature imaging method has advantages over other approaches. When the temperature around the tumor is calculated by using the propagation speed of ultrasound, there always exist overshoot artifacts along the boundary between different tissues. In this paper, we present a new method combined with empirical mode decomposition(EDM), similarity constraint, and continuity constraint to optimize the temperature images. Simulation and phantom experiment results compared with those from our previously proposed method prove that the EMD-based method can build a better temperature field image, which can adaptively yield better temperature images with less computation for assistant medical treatment control.     

基于光声谱的生物组织“指纹”光声诊断术*

肿瘤诊断主要采用医学影像结合组织活检病理予以确诊,但尚未实现高效的早期肿瘤筛查,现有影像术的诊断信息不全面和病理的有创、耗时长是关键问题。近年来快速发展起来的新型生物医学光声成像和光声谱分析技术,对生物组织的分子、化学和功能信息高度灵敏,可实现组织"指纹"的量化检测,且实时、无放射性、无电离性,与其他影像技术融合后具有实现无创"质谱"检测的巨大潜力。该文基于光声信号在光学和声学两个维度的谱分析,实现多种肿瘤和正常组织的光声组织"指纹"成像;提取的量化参数对肿瘤、癌前病变和正常组织进行了有效区分。这项技术有望实现高效、无创、低价的在体早期肿瘤筛查。