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第 38 卷 第 2 期                                                                       Vol. 38, No. 2
             2019 年 3 月                          Journal of Applied Acoustics                    March, 2019


             ⋄ 研究报告 ⋄



                         基于聚焦换能器的超声透射CT技术                                                     ∗





                                         蒋 剑 王月兵           †   沈 超 郑慧峰



                                            (中国计量大学计量测试工程学院         杭州   310018)

                摘要    超声透射 CT 技术能够重建物体横断面的图像，为了重建高质量图像，分别从换能器和图像重建算法两
                个方面展开研究。分析了弧形线聚焦换能器焦域处聚焦切片尺寸与换能器几何尺寸的关系及其对 CT 检测的
                影响。搭建了超声透射 CT 检测系统，以等角扇形束的扫描方式获取投影数据，并利用滤波反投影和最小二乘
                正交分解两种算法重建图像，对比发现最小二乘正交分解算法通用性更强，成像质量更佳。实验结果表明，利
                用聚焦换能器并结合最小二乘正交分解算法对物体进行 CT 检测，能够取得较好的成像结果，检测分辨力可达
                毫米量级。
                关键词     超声透射 CT，聚焦换能器，信噪比，图像重建算法
                中图法分类号: TH87,TB55           文献标识码: A          文章编号: 1000-310X(2019)02-0191-09
                DOI: 10.11684/j.issn.1000-310X.2019.02.007





                  Ultrasonic transmission CT technology based on the focused transducer



                              JIANG Jian    WANG Yuebing      SHEN Chao     ZHENG Huifeng


                       (College of Metrology & Measurement Engineering, China Jiliang University, Hangzhou 310018, China)

                 Abstract  The ultrasonic transmission CT technique can be used to reconstruct the image of the cross section.
                 In order to reconstruct a high-quality image, the research was carried out from two aspects: transducer and
                 image reconstruction algorithm. The relationship between the focused slice size of the arc line-focus transducer
                 and its geometric size, and the influence of the focus slice size on the CT detection were analyzed. The ultrasonic
                 transmission CT detection system was set up. The projection data were obtained by the scanning mode of
                 equiangular fan beam. Algorithms of filter back projection (FBP) and least squares QR-factorization (LSQR)
                 were used to reconstruct the image. By comparison, the LSQR algorithm is more universal and the imaging
                 quality is better. The experimental results show that, using the focused transducer and the LSQR algorithm
                 to detect objects, good imaging results with detection resolution reaching millimeter scale can be obtained.
                 Key words   Ultrasound transmission CT, Focused transducer, Signal-noise ratio, Image reconstruction
                 algorithm






             2018-08-14 收稿; 2018-10-17 定稿
             国家重点研发项目 (2017YFF0205004), 国家自然科学基金项目 (11474259), 浙江省 “仪器科学与技术” 重中之重学科人才培育项目
             ∗
             (JL150506), 浙江省大学生科研创新活动计划项目 (2018R409035)
             作者简介: 蒋剑 (1994- ), 男, 安徽六安人, 硕士研究生, 研究方向: 超声波无损检测技术。
             † 通讯作者 E-mail: wyb_1963@163.com
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