超声技术名称简介（二）

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                    <section><section powered-by="gulangu"><section><p><img src="image/20201019/85f30a9b666702bb4101533392db06ed_1.gif" /></p></section></section><section powered-by="gulangu"><section><section><p>超宽频带成像</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 在发射时有一很宽的频带范围，如<span>2M<span>HZ</span>~12M</span><span>HZ<span>，接收时分三种选择方式：&nbsp;&nbsp;</span></span></p><p><span><span>&nbsp; &nbsp; &nbsp; &nbsp; 1、选频接收：在接收回声中选择一特定的中心频率，保证能到达所要求的诊断深度，尽可能选择较高频率的回声，以获得最佳的图像质量。</span></span></p><p><span><span>&nbsp; &nbsp; &nbsp; &nbsp;2、动态接收：在接收回声时，随深度变化选取不同的频率，近场取高频，中场取中频，远场取低频，达到好的分辨率与好的穿透力的要求。</span></span></p><p><span><span>&nbsp; &nbsp; &nbsp; 3、宽频接收：在接收回声时，所有频率的回声均接收，在中近场包含不同频率回声，在远场由于高频成分衰减，只能接收到稍低频率的回声。</span></span></p></section></section></section><section powered-by="gulangu"><section><section><p>A型（AMPLITUDE）</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 1、幅度显示。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 2、显示探头接收到的反射或投射超声信号的幅度随时间变化的过程。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 3、A型显示的是一条幅度随时间变化的曲线，而不是图像。</p></section></section></section><section powered-by="gulangu"><section><section><p>B型（BRIGHTNESS）</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1、显示亮度调制的信号。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;2、在超声诊断仪的显示器上，以亮度调制的方式，显示声束扫描平面内人体组织的断面图像。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 3、B型显示给出的是人体的解刨结构图像。</p></section></section></section><section powered-by="gulangu"><section><section><p>M（MOTION）型</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 1、显示运动信息。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 2、显示特定的声束方向上各回波点随时间变化（运动）的情况。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 3、显示图中横坐标是时间，纵坐标是探测深度。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 4、M型显示常用于观察心脏等运动的脏器。</p></section></section></section><section powered-by="gulangu"><section><section><p>高频成像</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1、高频超声波在临床检查中可以分辨更细微的病灶，及提高声图像的轴向分辨力。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;2、目前用于临床常规B超探头频率范围为：2~10Mhz。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;3、在血管内及浅表器官成像中，已采用频率：20~40Mhz。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;4、高频超声、超声生物显微镜频率范围：40~100Mhz，主要用于皮肤成像、冠状动脉内成像及眼部成像。</p></section></section></section><section powered-by="gulangu"><section><section><p>微米取样技术</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1、指取样间隔小于0.1MM的技术。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;2、实际上当使用高频探头，并使探测深度为2cm，在一条声束上取500个样点时，取样间为40mm，这就实现微米取样技术。</p></section></section></section><section powered-by="gulangu"><section><section><p>动态孔径</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 1、换能器的孔径是指超声波波束形成时被激活的那部分压电晶体的面积。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 2、孔径小则近场的声束尺寸小，空间分辨率高，但在远场的发散较严重：反之，孔径愈大，近场的分辨率变差，但远场的发散相对较小。</p><p>&nbsp; &nbsp; &nbsp; &nbsp;3、为了使超声图像在近场与远场都有较高的空间分辨力，超声仪器在近场的发射和接收中采用小孔径，而在远场采用大孔径，这就是动态孔径的概念。</p></section></section></section><section powered-by="gulangu"><section><section><p>变迹</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 1、变迹技术可用于超声波发射，也可以用在超声波接收的时候。<br  /></p><p>&nbsp; &nbsp; &nbsp; &nbsp; 2、发射变迹是指给发射阵元组中的各个阵元施加不同电压的激励脉冲，接收变迹是指对各个阵元的输出信号给予不同的增益。</p><p>&nbsp; &nbsp; &nbsp; &nbsp;3、变迹技术被用来减小超声发射和接收时的栅瓣和边瓣。</p></section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><section><p>欢</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>迎</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>关</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>注</p></section></section></section></section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><p><img src="image/20201019/8685e7a278faffefe9c644d964b9f1df_10.jpg" /></p></section></section></section><section><section powered-by="gulangu"><section><section></section></section></section></section><section><section powered-by="gulangu"><section><section><p>关注我们</p><p>一起涨姿势！</p></section></section></section></section></section></section></section>