由于近代物理学和计算机技术的发展,推动了医学影像诊断技术的进步,相继涌现了B超、CT、ECT和MRI,共同形成了独立的影像诊断学.这些功效神奇的诊断设备真令人眼花缭乱,弄不清孰高孰低,不知道他们到底有什么区别.在此,笔者做简单介绍.1B超什么是超声波?人耳能听到的声音频率为20Hz～20 Due to the development of modern physics and computer technology, advances in medical imaging diagnosis technology have been promoted, and B ultrasound, CT, ECT and MRI have emerged together to form an independent imaging diagnosis. These magical diagnostic devices are really dazzling I do not know what is the difference between them in the end, here I make a brief introduction .1B what is the ultrasound? Human ear can hear the sound frequency of 20Hz ~ 20