MRI is also known as Magnetic Resonance Imaging (MRI), the full name of the English language is: Magnetic Resonance Imaging (MRI). The nuclei that are often utilized by the people are: 1H, 11B, 13C, 17O, 19F, 31P. At the beginning of the birth of the technology was known as Nuclear Magnetic Resonance Imaging (NMRI), and at the beginning of the 80s of the 20th Century, NMR Imaging (NMRI), which is a new technology in the medical field, is the most important technology in the medical field. The term NMR Imaging (NMR Imaging) became increasingly familiar to the public. With the installation of large magnets, there was concern that the letter "N" might have a negative impact on the development of MR imaging. In addition, the word "nuclear" also tends to give hospital staff an image of another nuclear medicine department in the magneto*** vibration chamber. Therefore, in order to emphasize the advantages of this technique, which does not produce ionizing radiation, and to differentiate it from nuclear medicine, which uses radioactive elements, radiologists and equipment manufacturers have agreed to shorten the term "magnetic resonance imaging" to "magnetic resonance imaging (MRI)". ".
Medical use
The most commonly used nucleus for magnetic **** vibration is the hydrogen nucleus proton (1H), because it has the strongest signal and is widely found in human tissue. Factors affecting magnetic **** vibration imaging include (a) the density of the proton, (b) the length of the relaxation time, (c) the flow of blood and cerebrospinal fluid, (d) paramagnetic substances (e) proteins.
The gray scale of a magnetic **** vibration image is characterized by greater brightness the stronger the signal of the magnetic **** vibration, and less brightness when the signal of the magnetic **** vibration is weak, ranging from white, to gray, to black.
Various tissue magnetic *** vibration image gray scale characteristics are as follows: adipose tissue, cancellous bone is white; cerebrospinal cord, bone marrow is whitish-gray; viscera, muscle is grayish-white; liquids, the normal rate of flow of blood is black; bone cortex, gas, air-containing lungs is black.
Nuclear magnetic **** vibration of another feature is the flow of liquid does not produce a signal called the flow effect or flow blanking effect. Thus blood vessels are grayish-white tubular structures, while blood is signal-free black. This makes blood vessels easy to separate from soft tissue. The normal spinal cord is surrounded by cerebrospinal fluid, which is black, and has white dura mater lined with fat so that the spinal cord shows up as a white, strongly signaling structure.
Magnetic **** vibration (MRI) has been used to image and diagnose systems throughout the body. The best results are the cranial brain, and its spinal cord, the heart large blood vessels, joints bones, soft tissues and pelvis. For cardiovascular diseases, it can not only observe the anatomical changes of the chambers, great vessels and valves, but also make ventricular analysis, qualitative and semi-quantitative diagnosis, and can make multiple cross-sectional maps, with high spatial resolution, displaying the whole picture of the heart and lesions, and their relationship with the surrounding structures, which is superior to other X-ray imaging, two-dimensional ultrasound, nuclide and CT examination. In the diagnosis of cerebral spinal cord lesions, coronal, sagittal and cross-sectional images can be made.