Overview of peter Mansfield's nuclear magnetic resonance.

Magnetic resonance imaging (MRI) is no stranger to petroleum people. Before its application in the medical field, the oil industry introduced this technology, such as nuclear magnetic logging, nuclear magnetic resonance core testing, nuclear magnetic resonance magnetometer, etc., which are widely used in petroleum ranks. Even in petroleum hospitals, there are nuclear magnetic resonance instruments for detecting human bodies, and I have received brain instruments. The basic principle of nuclear magnetic resonance imaging is that the detected object is placed in a uniform strong magnetic field, and the hydrogen nucleus in the object is excited by radio frequency pulse, which causes the hydrogen nucleus to vibrate and absorb energy. After the radio frequency pulse is turned off, the hydrogen nucleus sends out radio signals according to its unique frequency, and the absorbed energy is released, which is recorded by the receiver and processed by the computer to obtain a three-dimensional image.

Magnetic resonance imaging (MRI) was invented by American scientist Lauterpur in the early 197s when he was a professor in the Department of Chemistry and Radiology and taught at the State University of New York at Stony Brook. Lauterpur added an uneven magnetic field to the main magnetic field, that is, introduced a gradient magnetic field and induced the hydrogen nucleus in the crystal substance to vibrate by radio waves, and finally obtained a two-dimensional nuclear magnetic resonance image, which was later popularized and applied to the fields of biochemistry and biophysics; Mansfield, a British scientist, took the lead in applying MRI to clinic in 1976, and took the first MRI photo of human body.

in p>1982, the United States began to formally use magnetic resonance imaging in clinical medicine, and gradually became an advanced and rapid medical diagnosis method without damage. It has two advantages: first, there is no radiation harmful to the human body. The so-called nucleus only induces hydrogen nuclei in the human body, and the human body is in a magnetic field and will not be harmed; Second, the disease can be diagnosed at an early stage, because the phenomenon of nuclear magnetic resonance (MRI) identifies human tissues by detecting chemical changes in the human body, and X-ray and X-CT imaging techniques identify human tissues by physical (morphological) changes in the human body, and morphological changes indicate that the disease has developed to a certain extent. Because of this, magnetic resonance imaging cares about life, saves many patients, and benefits mankind. It is natural to win the prize. At present, there are about 22, MRI machines in the world for clinical human detection, and about 6 million people receive nuclear technology detection every year. MRI has made great contributions to the diagnosis and corresponding treatment of early lesions and won worldwide praise.

Medal

The phenomenon of nuclear magnetic resonance was awarded the Nobel Prize in physics as early as 1952. In the 197s, the oil industry introduced nuclear magnetic resonance technology to describe the static and dynamic state of oil, gas and water in the reservoir by using nuclear magnetic logging imaging, which contributed to the efficient exploration and development of oil and gas reservoirs. Using nuclear magnetic resonance magnetometer, we can directly find oil and gas reservoirs and trap the area of oil and gas fields in oil and gas exploration, determine the interface of oil, gas and water, and provide reliable oil and gas reserves; In the laboratory, the application of nuclear magnetic resonance imaging can describe the distribution in the rock core, and make suggestions for oil and gas exploitation to improve oil and gas recovery ... All these show that the application field of nuclear magnetic resonance imaging is extensive, and that the petroleum industry is a temple to absorb advanced technology and outstanding scientific research achievements of mankind. Of course, compared with the application effect of magnetic resonance imaging in physiology/medicine, there is still potential to be tapped in the application of this technology in the petroleum industry, and there are more topics to be innovated in the application. From the Nobel Prize of magnetic resonance imaging, we can see that the contribution of applied technology can not be underestimated, and it is no less than theoretical innovation from the perspective of benefit; From the fact that Lauterpur and Mansfield, two physics scientists, were awarded the Nobel Prize in Physiology/Medicine, it can be seen that the layman's "beating the nail on the head" means invention and innovation. Today, when the interdisciplinary science is flourishing, it is not uncommon for the interdisciplinary science to bear fruitful results. Accurate and noninvasive imaging of human internal organs is very important for medical diagnosis, treatment and follow-up feedback. This year's Nobel Prize winners in medicine and physiology have made groundbreaking inventions in imaging different structures using magnetic vibrations. These inventions have led to the development of modern magnetic resonance imaging (MRI), which represents a breakthrough in medical diagnosis and research.

the nucleus rotates in a strong magnetic field at a frequency determined by the strength of the magnetic field. If they absorb electromagnetic waves of the same frequency, their energy will increase (* * * vibration). When the nucleus returns to its original energy level, it will emit electromagnetic waves. These discoveries were awarded the Nobel Prize in Physics in 1952. In the next few decades, magnetic vibration is mainly used in the study of chemical structure of substances. In the early 197s, this year's Nobel Prize winners made pioneering contributions, leading the future application of magnetic resonance in medical imaging.

Magnetic resonance imaging, MRI, is now a routine method in medical diagnosis. There are more than 6 million MRI tests worldwide every year, and this method is still developing rapidly. MRI is usually superior to other imaging techniques, and has significantly improved the diagnosis of many diseases. MRI has eliminated several invasive examinations, thus reducing the risk and inconvenience of many patients.

hydrogen nucleus

water accounts for two-thirds of human body mass, and such a high water content explains why magnetic resonance imaging has been widely used in medicine. The water content in various tissues and organs is different. In many diseases, the pathological process leads to the change of water content, which is reflected in magnetic resonance imaging.

water molecules are composed of hydrogen and oxygen atoms. Hydrogen nuclei can play the role of a subtle compass. When the human body is placed in a strong magnetic field, the hydrogen nuclei will be arranged in order-just like "standing at attention" in military training. When the electromagnetic pulse is injected, the energy distribution of the nuclei changes. After the pulse, the nuclei send out * * * vibration waves and return to the previous state.

small differences in the vibrations of nuclei will be detected. Through advanced computer processing, a three-dimensional image can be built, and it can reflect the chemical structure of tissue, including the difference of water content and water molecule movement. This will produce a very detailed image of the tissues and organs in the detected area of the human body. This way can record the pathological changes. This year's Nobel Prize in Medicine and Physiology awards vital contributions to the development of medically important applications. In the early 197s, they made pioneering inventions to develop imaging technology of different structures, which laid the foundation for developing magnetic vibration into a useful imaging method.

Paul Lauterpur found that the introduction of magnetic field gradient made it possible for two-dimensional imaging of structures that could not be achieved by other methods. In 1973, he described how adding gradient magnetic field to the main magnetic field made it possible to show ordinary water surrounded by heavy water in pipeline cross-section imaging. Other imaging methods can't distinguish ordinary water from heavy water.

Peter Mansfield used magnetic field gradient to show the difference in vibration more accurately. He explained how the detected signals were quickly and effectively analyzed and converted into images. This is a key step to obtain practical methods. Mansfield also explained how fast imaging can be achieved through rapid gradient change (echo plane scanning). This technique became useful in clinical practice after 1 years. The medical application of magnetic resonance imaging has developed rapidly. The first MRI sanitary equipment was used in the early 198s. In 22, there were about 22, MRI cameras in the world, and more than 6 million MRI tests were carried out.

the great advantage of p>MRI is known so far, and it is harmless. This method does not use ionizing radiation, which is in contrast with ordinary X-ray (Nobel Prize in Physics in 191) or computer tomography (Nobel Prize in Medicine and Physiology in 1979). However, patients with magnetic metal or pacemakers can't be detected by MRI because of the strong magnetic field, and patients with claustrophobia may have difficulty in using MRI. Today, MRI is used to detect almost all human organs. This technique is especially valuable for detailed imaging of the brain and spinal cord. Almost all brain disorders will lead to changes in water volume reflected in MRI images. A water volume difference of less than 1% is enough to detect pathological changes. In multiple sclerosis, MRI detection is very good for disease diagnosis and follow-up feedback. Symptoms associated with multiple sclerosis are caused by local inflammation of the brain and spinal cord. With MRI, the location, intensity and curative effect of nervous system inflammation can be determined.

Another example is the patient's long-term low back pain with great pain and high social cost. In this case, it is important to distinguish between muscle pain and pain caused by pressure on the nerve spinal cord. MRI has been able to replace the methods that used to annoy patients. With MRI, it can be clear whether the disc herniation squeezes the nerve or not, and whether surgery is needed can be decided. Since MRI gives detailed three-dimensional images, people can get the exact information of the injury location. Such information is very important before operation. For example, in some microsurgical brain operations, surgeons can operate under the guidance of MRI images. The image is fine enough to allow electrodes to be placed in the central core of the brain to treat severe pain or dyskinesia in Parkinson's disease.

MRI detection is very important for cancer diagnosis, treatment and follow-up feedback. Images can accurately reveal the boundaries of tumors, which is beneficial to more accurate surgery and radiation therapy. It is very important to know whether the tumor has infiltrated into the surrounding tissues before surgery. MRI can distinguish tissues more accurately than other methods, so it contributes to improving surgery.

MRI can also improve the accuracy of determining tumor stage, which is very important for choosing treatment methods. For example, MRI can determine how deep the colon cancer has penetrated in the tissue and whether the lymph nodes there have been infected. MRI can replace previous invasive tests, thus alleviating the pain of many patients. One example is that the examination of pancreas and bile duct uses an endoscope injected with contrast medium. This leads to serious complications in some cases. Today, MRI can get the corresponding information.

Diagnostic arthroscopy (inserting optical devices into joints) can be replaced by MRI. MRI can complete the examination of articular cartilage and cruciate ligament in the knee in detail. Because MRI is non-invasive, the risk of infection is ruled out.