来自《耶鲁大学开放课程：生物医学工程探索 第21集 第21集》

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  Therefore, only a fraction of it is available to pass
  因此 X线在穿过身体时
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  all the way through your body and expose the X-ray film.
  只能通过一部分组织 并在胶片上成像
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  We're going to talk about
  今天我们要讲的是
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  several alternate forms of imaging today,
  一些有所改进的造影方法
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  many of which are similar to CT imaging.
  这些方法中有很多与CT成像类似
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  Now, CT imaging is a special form of X-ray imaging
  CT成像是一种特殊的X线成像
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  where you rotate the source of X-rays
  X光源和接收装置
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  and the detector around the object
  会围绕着患者旋转
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  you're trying to image around the patient.
  对指定部位进行拍摄
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  You take images at a large number of angles
  拍摄全身各角度的照片
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  and using mathematical approaches
  并采用数学方法
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  you reconstruct the three dimensional image
  重建身体的三维影像