x-ray, x-ray imaging, is a technique that uses x-rays to irradiate parts of the body and form images. Because x-rays penetrate human tissue, and different properties and densities of human tissue absorb x-rays differently, x-ray imaging is able to "see" the location and distribution of internal tissues and foreign objects in the human body under non-invasive conditions, thus providing a strong basis for medical diagnosis and treatment

CT is actually an x-ray. It's x-ray, but it's a more sophisticated form of x-ray imaging. Ordinary x-ray imaging can only form a few locations of the plane image, there are location overlap limitations, for example, a lesion from the bone is very close to the case, it is easy to be obscured is not easy to find, thus delaying the timely diagnosis and treatment; and ct is the so-called "computer-assisted tomography", computer-controlled x-rays are emitted and received, the body parts of the specified level of rotational scanning. The computer controls the emission and reception of x-rays, performs rotational scanning on a specified level of the human body, and solves for the strength of the received signals, so as to derive the absorptive capacity of the different areas of the level of x-rays, which is ultimately plotted by the computer into a tomographic map and provided to the doctor as the basis for diagnosis and treatment. Obviously, ct provides more and more accurate information than normal x-ray imaging, and the intensity of x-ray radiation received by the patient is greatly reduced at close to the effective resolution.

b Ultrasound is the use of mechanical waves - sound waves on a part of the body to scan, and its nature and "buckle diagnosis" can be said to be not fundamentally different. Instead of using normal frequency sound waves, it uses ultrasound waves with a frequency of MHz. Comparatively speaking, b ultrasound resolution is poorer, the error is larger; but because many soft tissues are very close to the absorption of x-rays, and its internal structure of ultrasound reflection and absorption differences, so the liver, gallbladder, spleen, kidneys, pelvis and other locations commonly used b ultrasound examination; in addition to ultrasound Doppler can be used to determine the speed of blood flow, which is on cardiovascular disease, cervical spine blood flow, tumor blood supply and other areas of obvious diagnostic significance. This is of obvious diagnostic significance.

B ultrasound is generally a soft-tissue examination, CT, X-ray mainly bone CT check intracranial hemorrhage is also good