Virtually to cut a person across and see what's inside, has always been the dream of a diagnostician. Now for this not only computer tomographs using X-rays but also MRI. The basis of these devices is the use of the effect of nuclear magnetic resonance. Magnetic resonance imaging is very widely used throughout the world, and clinical experience indicates a high resolution and contrast of the resulting layered images of organs and tissues. In fact, it is possible to create images that are equal in quality to photographs of anatomical sections.

One of the advantages of MRI is the lack of sources of ionizing radiation, and therefore diagnostic studies are considered to be practically safe for patients.

The high quality and reliability of the data obtained during the survey makes MRI one of the most effective methods of diagnosing diseases. The possibility of MRI of the thoracic spine and other parts of the body allows you to get a complete picture of human health. Most often this examination is assigned to patients with suspected cancer, impaired musculoskeletal system, nervous system.

Such a survey allows you to accurately detect changes in tissues, which is especially important after getting a person severe injuries, undergoing a course of treatment or surgery.

A little bit about the history. The NMR effect was discovered in 1946 by scientific groups at Stanford and Harvard Universities. His pioneers F. Fleas and E. Parsell received the Nobel Prize in Physics in 1952. Scientists have established that the nuclei of some atoms, when placed in a magnetic field, absorb the energy of the electromagnetic pulse, and upon termination of the pulse action radiate it in the form of a radio signal. For the occurrence of such a nuclear resonance, the induction of the magnetic field and the frequency of the electromagnetic pulse should correspond in a certain way to each other.

For medical purposes, the NMR effect was used in the early 1980s. The first tomographs were demonstrated at the Congress of Radiologists in Paris in 1982.

At the heart of modern magnetic resonance tomography is the principle of magnetic resonance of hydrogen nuclei. Since water is contained in the organs and tissues of a person in a significant amount, then, respectively, hydrogen is the most widely distributed element in the human body.

In practice, the diagnostic study is as follows. The patient is placed in a strong static magnetic field of the tomograph, after which the nuclei of hydrogen atoms, which are small magnets in the human body, are oriented in the direction of the field. The doctor who conducts the study selects the area to be tested by adding a weak alternating magnetic field with the help of so-called gradient coils. Then the tomograph sends an electromagnetic signal (radio wave). This is done with the help of a radiator of radio frequency pulses.

Hydrogen atoms are excited and generate a response signal that is picked up by the receiving RF coils-tomograph detectors. Different types of tissues (bones, muscles and others) contain different amounts of hydrogen atoms, so they generate signals with different characteristics. After decoding signals by a certain technique, an image of the corresponding layer.

In the process of research, the table with the patient gradually moves inside the scanner, made in the form of a ring. When scanning, the patient is in the tunnel of the tomograph, where there is enough light and there is a fan that provides fresh air. Only it is necessary, that the person did not stir, as even small displacements can essentially lower quality of received images. The duration of the diagnostic study depends on the purpose and volume of the tissues. But even the most full-scale "scan" lasts no more than 45-60 minutes. At us such researches are spent extremely seldom.

Usually the patient is in the cell for up to half an hour.

Initially, MR imaging was provided as a method that gave an image of thin transverse sections of a human body. With the development of software from layered images, physicians moved (as well as in X-ray computed tomography) to voluminous. Now this method is especially effective in the study of dynamic processes (for example, the state of blood flow) in organs and tissues. Unfortunately, they are not often used ... real-vin. com.

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