DR examination, commonly known as "Taking a picture", uses the penetrating power of X-rays, through the body different tissues, different organs, organs of different density and different development of a radiographic examination method, the examination is like taking a flat image of the body. If you encounter a blocked area, the negative will not be exposed, but the film will appear white after development.
Application: Digital X-ray processor is a relatively simple way to observe the bones of the examination, the price is relatively cheap. If you suspect acute trauma to the limbs, spine and other parts of the injury to the bone, sudden acute pain or difficult to control the chronic pain, will generally choose X-ray first.
CT scans a section of a certain thickness of the human body with an X-ray beam. The X-ray transmitted through the section is received by the detector and transformed into visible light, after being processed by computer and being printed by X-ray film printer, not only the interference is less, but also the structure can be observed from several planes to reflect the three-dimensional shape of the skeleton.
Application: CT in a sense can be said to be an enhanced version of the X-ray, if the digital radiography X-ray machine can not see clearly, may have to choose CT closer look. General important parts of the CT examination, such as skull, chest and abdomen, spine, pelvis and other general superior to conventional X-ray.
Magnetic resonance imaging, which uses magnetic resonance phenomena to create images, uses a strong magnetic field to make the water in the body vibrate, then calm down and feel the vibrations inside, the difference between normal tissue and affected site can be observed after imaging.
The difference between CT and MRI: MRI can make multi-angle slices, without any damage to the human body, and no radioactivity. In general, the demonstration of the anatomy and pathological changes of the brain, spinal column and spinal cord is better than that of the CT examination, in particular, the joints, muscles, central nervous system and other soft tissue examination structure more clearly.
The imaging principles of various imaging examinations are different, and each has its advantages and disadvantages. The method of imaging examination is different for different parts and different emphasis of observation. The doctor will choose one or more suitable examination methods according to the concrete actual situation, in order to achieve the accurate diagnosis goal, therefore we need to follow the doctor's advice, actively cooperate with the doctor.