Mri

MRI
MRI is magnetic resonance imaging, English name is: Magnetic Resonance Imaging. In the beginning of the birth of this technology has been referred to as magnetic resonance imaging, to the 20th century, early 80s, as new medical technology, NMR imaging (NMR imaging) the term more familiar to the public. With the installation of a large magnet, some people began to worry about the letter In addition, Therefore, in order to highlight this examination technique does not produce the benefits of ionizing radiation, and nuclear medicine with the use of radioactive elements, the phase difference between the radiologist and equipment manufacturers have agreed to ).
directory
technical characteristics of the working principle imaging equipment for medical use by the principle characteristics of MRI examination of medical indications for MRI examination abbreviated history of technical characteristics of nuclear magnetic resonance magnetic resonance imaging is a kind of tomography, which uses resonance phenomenon of electromagnetic signals obtained from the human body and reconstruction of the human body information. 1946, Stanford University Flelix Bloch and Edward Purcell of Harvard University found a separate NMR phenomenon. Magnetic resonance imaging is based on the physical phenomenon. 1972 Paul Lauterbur developed a set of NMR signals for space coding method, this method can reconstruct the body image.
MRI
Magnetic resonance tomography imaging techniques and other techniques (eg CT) are some things in common, such as they can show some kind of physical quantity (eg density) distribution in space; but also has its own characteristics , Magnetic resonance imaging can be obtained tomography image in any direction, three-dimensional body images, and even get space - spectral distribution of the four-dimensional images. The same as PET and SPET for imaging magnetic resonance signal directly from the object itself, it can be said that magnetic resonance imaging is also an emission tomography imaging. However, PET and SPET with magnetic resonance imaging is different radioactive isotopes can be injected without imaging. This also makes magnetic resonance imaging technology more secure. From magnetic resonance images, we can get a variety of physical parameters of materials, such as proton density, spin - lattice relaxation time T1, spin - spin relaxation time T2, diffusion coefficient, susceptibility, chemical shift, etc. . Contrast other imaging technologies (such as PET, ultrasound CT) magnetic resonance imaging method is more diverse, more complex imaging principle, and the resulting information is also more abundant. Therefore, in magnetic resonance imaging as a popular medical imaging research. MRI also inadequate. Its spatial resolution is less than CT,cheap vibram five fingers, in patients with cardiac pacemakers or metallic foreign bodies in some parts can not be MRI examination, the other expensive. Working principle of nuclear magnetic resonance is a physical phenomenon, as an analytical tool widely used in physical, chemical and biological fields, to only use it for the 1973 Clinical detection. In order to avoid radiation and nuclear medicine imaging of confusion, it is called magnetic resonance imaging (MR). MR is a bio-magnetic spin-imaging technology, it is the use of nuclear spin motion characteristics, in an applied magnetic field, generated by the RF signal after pulse excitation, with the detector to detect and entered into the computer, after computer processing on the screen after conversion Show images. MRI imaging principle principle: the nucleus with positively charged nuclei of many elements, such as 1H, 19FT, and 31P, etc. spin campaign. Typically, the nuclear spin axis of the arrangement is irregular, but to place it in an external magnetic field, the spatial orientation of nuclear spin transition from disorder to order. Thus, while the nuclear spin axis and magnetic field to spin the angle between the vector magnetic field around the precession vector, which is called precession larmor into, like spinning gyroscope in the Earth's gravity under the rotation. Magnetization vector spin system gradually increased from zero, when the system reaches equilibrium, the value of magnetization to stabilize. If this time the role of the nuclear spin system by outsiders, such as certain radio frequency to cause resonance excitation nucleus. In this way, but also in the nuclear spin precession frequency direction, this superposition state is called precession nutation. In the RF pulse stops, the nuclei spin system has intensified, can not maintain this state, will revert to the original arrangement of the magnetic field in the state, while the release of weak energy, a radio signal, many signals detected in this and make The spatial resolution can be carried out to obtain nuclear distribution of the image campaign. Nuclei from the intensification of the state back to the equilibrium ordered state process is called relaxation. It is called the relaxation time of the time required. There are two that T1 relaxation time and T2, T1 is the spin - lattice or longitudinal relaxation time T2, T2 is the spin - spin or transverse relaxation time. The most common medical use of nuclear magnetic resonance of hydrogen nuclei are protons (1H), because it is the strongest signal in human tissues are also widespread. Magnetic resonance imaging of factors, including: (a) proton density; (b) the length of the relaxation time; (c) the flow of blood and cerebrospinal fluid; (d) paramagnetic (e) protein. Magnetic resonance imaging gray scale features, magnetic resonance signal stronger, the brightness of the greater resonance of the signal is weak, then the brightness is also small, from white, gray to black. Magnetic resonance imaging features of various organizations are gray; fatty tissue, cancellous bone white; brain spinal cord, bone marrow was white and gray; internal organs, muscles are pale; liquid, the normal speed of blood flow was black; bone cortex, gas, gas black lung. Another feature of NMR is a signal flow of the liquid does not flow as a blank flow effect or effects. So is the white tubular vascular structure, and the black blood is no signal. This soft tissue is easy to separate the blood vessels. Surrounded by normal cerebrospinal fluid around the spinal cord, cerebrospinal fluid is black, and white are set off fat dura, the spinal cord showed a strong signal for the white structure. NMR has been applied to the whole body diagnostic imaging system. The best is the brain, and spinal cord, heart and great blood vessels, bone joints, soft tissue and pelvic cavity and so on. On cardiovascular disease can not only observe the chamber, large blood vessels and valves of the anatomical changes, and can be used for cardiac analysis, qualitative and quantitative diagnosis, can be used for multiple section map, spatial resolution, showing the heart and pathological picture , and its relationship with surrounding structures, better than the other X-ray imaging, two-dimensional ultrasound, radionuclide and CT. Spinal cord lesions in the brain, it can be coronal, sagittal and transverse images. MR features of medical equipment to provide not only greater than the amount of information in medical imaging in many other imaging, and different from the existing imaging, therefore, its diagnosis has great potential advantages. It can make a cross-section, sagittal, coronal, and a variety of beveled tomography images, does not produce artifacts in the CT test; without injection of contrast agent; no ionizing radiation, no adverse effects on the body. MR for detection of intracerebral hematoma, cerebral hematoma, brain tumors, intracranial aneurysms, arteriovenous malformation, cerebral ischemia, spinal cord tumor, syringomyelia brain and spinal cord and other common diseases, water is very effective, while lumbar After the disc protrusion, the diagnosis of primary liver cancer and other diseases is also very effective. Purpose of inspection: brain and spinal column, spinal cord lesions, ENT diseases, heart disease, mediastinal mass, bone and joint and muscle lesions, uterus, ovary,vibram five fingers running shoes, bladder, prostate, liver, kidney, pancreas and other parts of the lesion. Advantages: 1. MRI of the human body without ionizing radiation injury; 2. Access to the native three-dimensional MRI imaging section can be obtained without the need for multi-dimensional reconstruction of the image; 3. Soft tissue structure shows clearly the central nervous system, bladder, rectum, uterus, vagina, joints, muscles and other tests is superior to CT. 4. Multiple sequence imaging, multiple image types, the clear lesions provide a richer image information. Disadvantages: 1. And, like CT, MRI are diagnostic imaging, MRI is still difficult for many lesions diagnosed alone, unlike endoscopic images could be obtained both the diagnosis and pathology; 2. Inspection of the lungs or no better than X-CT, the liver, pancreas, adrenal gland, prostate check better than CT is superior, but the cost is much to high; 3. Than the lesions of the gastrointestinal tract endoscopy; 4. The sensitivity of the fracture as CT and X-ray film; 5. Metal objects left inside who should not receive MRI. 6. Critically ill patients should not be done 7. Who within 3 months of pregnancy unless the need is not recommended for MRI examination 8. With a pacemaker who can not MRI, MRI equipment can not be close to 9. Most of the more closed space MRI equipment checks Some patients do not meet to complete the inspection because of fear 10. Check a longer time required for MRI machines due note and MRI room there is a very strong magnetic field, therefore, those with pacemakers, and vascular surgery remain metal clip, metal stent, or other coronary artery, esophagus, prostate, bile duct surgery of metal stents, are strictly prohibited for MRI, or, as the metal attracted by a strong magnetic field moves, which may have serious consequences life-threatening. MRI is usually in the hospital room door, there are eye-catching red or yellow flags indicate strictly prohibited MRI situation. There can not remove the body and other metal objects, such as metal internal fixation of artificial joints, metal dentures, stand, silver clip, shrapnel and other metal retention by, the relative contraindications for the check, you must check, should be closely observed to prevent check strong magnetic field in the metal movement in the adjacent large blood vessels and damage major organizations, have serious consequences, such as no special need for an MRI generally do not. IUD and the activities of metal metal dentures must be removed before those checks. Sometimes the metal left in the body may affect the image quality of iron ions, and even affect the correct diagnosis. Before entering the MRI room, the body should be removed with a cell phone, pager,timberland boots online, magnetic cards, watches, coins, keys, lighters, metal belt, metal necklaces, metal earrings, metal buttons and other metal jewelry or metal objects. Otherwise, the examination may affect the uniformity of the magnetic field, causing the image of the interference, the formation of artifacts, is not conducive to the display of lesions; and because of the role of a strong magnetic field, metal objects may be sucked into the MRI machine, and thus very expensive MRI Machine damage; In addition, cell phones, pagers, magnetic cards, watches and other items also may be subject to strong magnetic fields, which leads to unnecessary loss of personal property.
MRI
recent years, with advances in technology and development, many orthopedic fixation, internal fixation, especially the spine, starting with titanium metal or titanium. Because titanium is not magnetic attraction, in a magnetic field will not move. Therefore, internal fixation titanium body with patients, the MRI examination is safe; and titanium not and will not interfere with magnetic resonance images. This is for people with spinal disease and in need of spine surgery is very valuable. But made of titanium and titanium fixation expensive, to a certain extent, affect its application. Indications for a MRI examination, nervous system diseases: cerebral infarction, brain tumors, inflammation, degeneration, congenital deformity, trauma, etc., for the application of the first body system, the current accumulated a wealth of experience, lesion location, more accurate diagnosis in time, can be found in early lesions. 2, the cardiovascular system: can be used for heart disease, cardiomyopathy, cardiac tumors, pericardial effusion, and thrombus, intimal flap of the dissection and other diagnosis. 3, chest disease: mediastinal tumor within the lymph node and pleural disease, etc., can display large lung mass and the relationship between the trachea and blood vessels. 4, abdominal organs: liver, liver hemangioma and hepatic cyst diagnosis and differential diagnosis of abdominal tumor diagnosis and differential diagnosis, especially in retroperitoneal lesions. 5, the pelvic organs; uterine fibroids, uterine other tumors, ovarian tumors, pelvic mass, the qualitative orientation, rectum, prostate and bladder tumor and so on. 6, bone and joint: bone infection, tumor, trauma of the diagnosis and extent of disease, especially for some minor changes, such as bone bruise, which are great value, articular cartilage, ligament, meniscus, synovium, synovial capsule, etc. lesions and bone marrow lesions have a higher diagnostic value. 7, general soft tissue lesions: either from the nerves,timberland 6 boots, blood vessels, lymph vessels, muscle, connective tissue tumors, infections, degenerative diseases, etc., can be made more accurate positioning, qualitative diagnosis. MRI (Matz's Ruby Interpreter) the standard Ruby implementation, the standard Ruby interpreter MRI examination acronym MRA MR angiography, is divided into use of contrast agents and does not use contrast agents. MRCP MR cholangiopancreatography shows extrahepatic bile duct and gallbladder, and bile duct stones to determine whether the expansion. Urinary MRU MR imaging, showed the ureter and bladder to determine whether the urinary tract dilatation and malformation and other diseases. MRM MR nerve imaging, mainly used in diagnosis of peripheral nerve diseases. MR shortcomings also exist less than inadequate. Its spatial resolution is less than CT, in patients with cardiac pacemakers or metallic foreign bodies in some parts can not be MR examination, while expensive, nuclear magnetic resonance scan time is relatively long history of the history of nuclear magnetic resonance 1930s, physicists found Isidora than the nuclei in a magnetic field along the magnetic field will be forward or reverse order was arranged parallel to the radio waves imposed after the direction of nuclear spin flip. This is the man on the nuclear and magnetic fields and RF fields applied first to recognize the interaction. Since the study, Rabbi in 1944 won the Nobel Prize in Physics. In 1946 two American scientists found that Bloch and Purcell, will have an odd number of nuclear (including protons and neutrons) of the nuclei placed in a magnetic field, Zaishi to a specific frequency of RF field, RF field absorbed nucleus occurs energy of the phenomenon, which is that people initially understand the phenomenon of nuclear magnetic resonance. To this end they both won the 1950 Nobel Prize in Physics. The phenomenon of people soon after the discovery of nuclear magnetic resonance to produce a practical use, chemists use molecular structure of the hydrogen atoms around the impact of the magnetic field, developed a nuclear magnetic resonance spectroscopy for the analysis of molecular structure, over time, magnetic resonance spectrum of technology development, from initial development to one-dimensional 13C NMR spectrum, two-dimensional NMR and other senior spectrum, NMR's ability to resolve the molecular structure of growing into the 1990s, people even develop to rely on nuclear magnetic resonance information to determine the tertiary structure of protein technology, making the solution phase the exact determination of the molecular structure of the protein possible. On the other hand, medical scientists have found that the hydrogen atoms of water molecules can produce nuclear magnetic resonance phenomenon, the phenomenon can be used to obtain the distribution of water molecules in the body of information to accurately draw the internal structure of the human body, on the basis of this theory in 1969, Southern Medical Center in New York State University Medical 博士达马迪 An NMR relaxation time by measuring the success of the cancer cells and normal mice to distinguish cells in the Dama Dean, inspired by new technology SUNY at Stony Brook physicist Paul 罗劳特伯尔 in 1973 developed a technique based on magnetic resonance imaging phenomenon (MRI), and the successful application of his devices to draw out a live clam in the internal structure of the image. Lauth, after Burr, MRI technology matures, increasingly wide range of applications to become a routine medical tests, widely used in Parkinson's disease, multiple sclerosis and other brain and spinal cord lesions and cancer treatment and diagnosis. In 2003, Paul 罗劳特伯尔 and professor at the University of Nottingham Peter Mansfield for their contributions to magnetic resonance imaging technology acquired when the Nobel Prize in Physiology or Medicine. Atlas Atlas entry for more extended reading: 1
Medical Imaging Technology
2
medical literature: http://www.qnr.cn/med/data/
Open Category : IT, medical, technical, medical imaging I read the information to improve the

Chaussures Nike