基于射线模型的超声声速层析算法研究进展

Ray-based sound speed reconstruction in ultrasound computed tomography:a review

得益于超声换能器硬件的进步和数据采集速度的提升,超声层析成像近年来得到了越来越多的关注,特别是在乳腺成像领域。超声层析成像中的声速图像分布可以为乳腺组织表征提供良好的定量分析数据,进而使得超声层析成像在乳腺癌的诊断方面有着良好的应用前景。目前,超声声速层析重建方法主要包括基于射线模型和全波模型的两大类算法。基于射线模型的重建方法使用了超声波的高频近似,假设超声波近似以直线或弯曲射线传播。由于数学模型简单,基于射线模型的声速重建算法是超声层析成像中一类重要的图像重建方法。该文将从射线前向过程、声波的第一到达时间提取以及声速重建的反问题等方面阐述基于射线模型的声速重建算法研究现状,并展望其在成像速度和成像质量方面的发展趋势。

Thanks to the fast developments of ultrasound transducer technology and data acquisition hardware,ultrasound computed tomography(USCT)has attracted more and more attention in recent years,especially in the field of breast imaging.USCT can provide quantitative sound speed information of soft tissues and is an important medical imaging method for disease diagnosis.To date,image reconstruction approaches in USCT mainly include ray-based reconstruction methods and full-wave-based reconstruction methods.Ray-based reconstruction methods use high-frequency approximation of ultrasound waves and assume that ultrasound travels in straight or bent rays.Due to the simplicity of the mathematical model,it is computationally efficient and more widely used than full-wave-based reconstruction methods.This work reviews ray-based forward models,the extraction of the first arrival time,and ray-based sound speed reconstruction algorithms in USCT and discusses future development trends.