来自《耶鲁大学开放课程：生物医学工程探索 第21集 第21集》

• 
  
  and it is mentioned in the chapter.
  但在这一章里提到了
• 
  
  What I want to talk about MR is different way of forming images,
  我想讲的是 磁共振具有不同的成像方式
• 
  
  uses a different kind of physics,
  利用不同的成像原理
• 
  
  and so the elements of intrinsic contrast are different.
  所以形成内部对比的基本单元有所不同
• 
  
  We'll talk about what makes -- MR images in a few moments.
  待会我们会讲是什么构成了磁共振图像
• 
  
  Bone does not appear well on MR images, whereas,
  然而对骨进行磁共振造影 效果并不好
• 
  
  bone appeared very well in X-rays and CT's for example.
  采用X线或者CT则会获得良好的效果
• 
  
  If you've taken chemistry,
  如果你们已经在大学
• 
  
  some chemistry in college or in high school,
  或者高中上过化学课
• 
  
  you've probably heard of NMR, nuclear magnetic resonance.
  可能会听说过NMR 即核磁共振
• 
  
  It was discovered by chemists as a way of
  化学家发明了这种方法
• 
  
  analyzing chemical samples.
  用来分析化学物质