X-ray examination is through the X-ray irradiation of the human body, based on the density of the body's various tissues and organs to visualize the different, generally for the chest and bone examination is more commonly used.
CT, also known as computed tomography, can scan the internal structure of the human body in layers, and is applicable to all tissues and organs of the body. For positive lesions that have been detected, CT examination can also provide a more detailed description of the location and scope of the lesion, and the accuracy is higher than that of X-ray. (It is especially important in the diagnosis of tumors.)
MRI, also known as nuclear magnetic **** vibration, is different from CT's cross-sectional scanning, he is a longitudinal scanning to check the brain, spine, nerves are more common. In the brain hemorrhage, cerebral infarction, as well as spinal deformity, disc herniation and other checks are more commonly used.
DSA is digital subtraction angiography, through the injection of contrast medium to make blood vessels imaging, such as interventional examination will use this technology, in the cerebral blood vessels, coronary blood vessels (nutrient blood vessels of the myocardium) and so on, more use, can avoid the influence of bones, organs, more intuitive judgment of blood vessels and changes in the shape. At the same time, it is also possible to inject drugs into the lesion at the same time as developing the image, which can also have a therapeutic effect, but this would have to be counted in the field of interventional therapy.
Other imaging tests include ultrasound, molybdenum X-ray, radionuclide imaging, and endoscopy, all of which are useful for a variety of diseases.
Also, the previously introduced X-ray, CT, DSA, such tests are radiation, prolonged exposure to the human body has a bad effect, MRI is not harmful to the human body, but the price is more expensive, and, MRI can not replace the role of other tests.