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导论最近几年对超声透射成象的兴趣逐渐增加,主要是由于Green等工作的刺激。这种成象由超声透镜组实现,医生得到与X线透视相似的图象。组织的不同衰减特性构成图象的信息。由于成象透镜的孔径大,因而横向分辨率高,能够看到肌腱、血管和肌组织等。采用象Creen及其同事用于检测的压电线阵,检测一个病人所需的曝光至少比用常规回声法小一个数量级。这种成象即可使用脉冲超声,也可以使用连续超声。由于来自焦平面外可能的错误信息已被减低,故由非相干声照射可以得到高诊断价值的图象。本文介绍一种非相干声照射的简单方法。用这种声源进行透射成象实验,说明了漫射、非相干声照射的附加优点:照射物体均匀,改进了横向分辨率。此外,对有明显
INTRODUCTION The interest in ultrasound transmission imaging has been increasing in recent years, mainly due to the stimulus of Green et al. This imaging is performed by an ultrasound lens set, and the physician obtains an image similar to fluoroscopy. The different attenuation characteristics of the tissue make up the image information. Due to the large aperture of the imaging lens, the transverse resolution is high, and the tendons, blood vessels and muscular tissues can be seen. Using piezoelectric arrays such as those used by Creen and his colleagues for detection, the exposure required to detect a patient is at least an order of magnitude smaller than with conventional echo methods. This imaging can use pulsed ultrasound, you can also use continuous ultrasound. Due to the fact that the possible error information from the focal plane has been reduced, highly diagnostic images can be obtained from incoherent acoustic radiation. This article describes a simple method of incoherent acoustic illumination. Transflective imaging experiments using this source illustrate the additional benefits of diffuse, incoherent acoustic illumination: uniform illumination of the object and improved lateral resolution. In addition, there are obvious