CT and DR belong to the same radiology examination methods, but they have many differences: First, CT is the use of radiation on the human body tomography, it is a relatively high resolution of the density, while DR on the human body is overlapping images, density resolution is relatively low, easy to miss the diagnosis; Second, the indications of the two are different, CT is suitable for almost the whole body sweep, from the head to the foot, except for gynecology, basically all involved The two indications are different, CT is suitable for almost whole body scanning, from head to foot, except gynecology, basically all involved, while DR is generally used for chest and skeletal system examination, the scope of use is relatively small; Third, the radiation to the human body is different, CT is relatively more radiation to the human body; Fourth, the price of the two is different, the price of CT is higher.