When it comes to X-ray, CT, ultrasound, MRI and other tests, many people are deterred by the fear of "radiation problems".

In fact, these types of tests are all imaging tests, that is, using machines to "see through" the body.

X-ray examination, as the name suggests, is the use of X-rays to penetrate the body to form images, similar to taking pictures, the radiation dose of X-ray examination is similar to the radiation received by a flight. x-ray examination can be taken skull film, chest film, abdominal flat film, limbs of the bones and joints of the film. X-rays are also used for stomach, esophagus, and intestinal disorders, such as barium meal tests and gastrointestinal imaging.

CT also uses rays to penetrate the body, but unlike X-rays, multi-row spiral CT exams now image the body by capturing every voxel of the body within the scanning area. The radiation dose of chest low-dose CT is about 0.2-0.5mSv, which is almost the dose of 10 chest radiographs, so it is very safe.CT is most commonly used in the examination of the head, chest, abdomen and spinal disorders, etc. CT is also an option for some limb and bone problems that cannot be clearly seen with X-ray examination.

Ultrasound ultrasound examination is the use of sound wave reflection, get different echoes to form an image, and throw a stone into the water to listen to the echo to measure the depth of the same reason. Ultrasound is a non-radioactive procedure that utilizes sound waves to create an image, and it is used to screen the abdominal and pelvic organs, including the breast, thyroid, liver, kidneys, pancreas, gallbladder, spleen, bladder, uterus, and ovaries for lesions. Ultrasound is also often used for heart examinations.

Magnetic resonance imaging (MRI) is often referred to as nuclear magnetic resonance (NMR). Because of the word "nuclear" in its name, there is a common misconception that it may have radiation and emit radiation, but in fact, the nucleus refers to the nucleus of the hydrogen atom. In fact, this nucleus refers to the nucleus of the hydrogen atom. There is no radiation, and there is no radiation or harm to the human body. Therefore, nuclear magnetism has no radiation. There are many parts of the body that can be examined by MRI, including the brain, blood vessels, muscles, ligaments, spine and so on.