What is magnetic resonance imaging? I believe everyone has a certain understanding of it. Do you know what diseases can be detected by magnetic resonance imaging? What are the precautions for doing magnetic resonance imaging? Let's learn about nuclear magnetic resonance together!
1、 What is magnetic resonance imaging?
Magnetic resonance imaging (MRI), also known as magnetic resonance imaging, is a current imaging examination method. Its basic principle is to record the nuclear motion of hydrogen atoms in tissues and organs under the action of a strong external magnetic field. The magnetic resonance signal is collected through an induction coil, and the image of the examination site is obtained after calculation and processing. Does nuclear magnetic resonance have radiation? This is a question that many patients often ask. Mainly, when people hear the word 'nucleus', they feel a bit scared. In fact, it has nothing to do with nuclei. It is not nuclear medicine or nuclear physics, but refers to atomic nuclei. The resonance of hydrogen nuclei occurs when the applied frequency matches its frequency. So, MRI examination does not involve radiation. Magnetic resonance imaging (MRI) has a wide range of applications and does not emit radiation to the human body. It is a relatively safe examination method that can be used to examine related diseases such as the head, chest, breast, abdomen, pelvic cavity, spine, as well as muscles and joints. Magnetic resonance imaging has a relatively high resolution for soft tissue, so it can complement CT examination in some aspects to jointly determine the specific situation of lesions.
2、 What are the advantages of magnetic resonance imaging?
Among all medical imaging techniques, magnetic resonance imaging has the highest resolution for soft tissues, so it has higher clarity for organs such as muscles, tendons, fascia, fat, spine, and brain tissue. It can effectively distinguish the meniscus, cruciate ligament, articular cartilage, uterine muscle layer, endometrial layer, prostate muscle layer and glandular layer of the knee joint.
2. Magnetic resonance imaging uses a three-dimensional gradient field in space, which can achieve scanning and image reconstruction from any angle without moving the patient or scanning bed. Magnetic resonance imaging can directly slice in any direction, and the examinee does not need to move their position. Based on the slice in each direction, the structure of the inspected organ or tissue can be clearly presented, completely eliminating observation blind spots. In recent years, volume scanning has been developed and applied, which can reconstruct anatomical structures or lesion locations in different planes, surfaces, or irregular sections in a three-dimensional manner.
3. Magnetic resonance imaging (MRI) has the characteristics of being non-invasive and radiation free, preventing damage caused by radiation from X-rays or radionuclide imaging. Magnetic resonance scanning will not harm the human body.
4. Magnetic resonance imaging has a large number of imaging parameters and a huge amount of information. For example, spin echo technology can obtain three types of images with different properties: T1 weighted image, T2 weighted image, and proton density weighted image.
5. More sensitive to lesion display, which can make the lesion display earlier and clearer. The examination images are clearer, allowing for a clearer observation of subtle anatomical structures such as nerves and blood vessels.
3、 What diseases can magnetic resonance imaging detect in the human body?
Magnetic resonance imaging is suitable for examining all parts of the human body and diagnosing various diseases. 1. Magnetic resonance imaging is suitable for the examination of various cranial diseases, including the vast majority of congenital developmental abnormalities or deformities of the skull, brain tumors, cerebrovascular diseases, cranial injuries, cerebral degenerative diseases, white matter diseases, and brain inflammation. Magnetic resonance imaging can make accurate diagnoses.
2. Magnetic resonance imaging can directly display the vascular structure of the mediastinum and pulmonary hilum, which helps to evaluate the relationship between lesions and the mediastinum and pulmonary hilum. Patients with pulmonary tuberculosis can locate the site of tuberculosis through magnetic resonance imaging, and can also grasp the type of tuberculosis, further comprehensively understanding the development of tuberculosis.
3. Magnetic resonance imaging can provide localization and qualitative diagnosis for spinal degenerative diseases, spinal and spinal cord injuries, vertebral and spinal canal tumors, and congenital deformities of the spine and spinal cord.
4. Magnetic resonance imaging has unique advantages in examining the bone and joint system, as it can effectively display structures such as muscles, tendons, ligaments, articular cartilage, meniscus, synovium, etc.
5. Magnetic resonance imaging can accurately evaluate various cardiovascular diseases, including congenital heart disease, various acquired cardiomyopathy, valve disease, pericardial lesions, heart tumors, etc.
6. Magnetic resonance imaging can also detect small lesions in solid organs such as the liver, pancreas, spleen, and kidneys, and make good diagnoses for larger lesions in the abdomen.
7. Magnetic resonance imaging can effectively display structures such as the uterus, ovaries, prostate, rectum, bladder, etc. Magnetic resonance imaging is also used for the examination of breast diseases.
4、 Issues to be aware of in magnetic resonance imaging (MRI) examination
Nowadays, we often use MRI examination methods in clinical practice, which basically do not harm our body. However, due to the use of strong external magnetic fields, the following issues should be noted during the examination.
1. Firstly, it is necessary to inform the doctor whether there are absolute contraindications for magnetic resonance imaging (MRI) examination, such as whether the heart has a pacemaker. Except for a few cases where MRI is clearly indicated to be possible, the vast majority of patients with pacemakers cannot undergo MRI examination, which may lead to danger, such as the possibility of pacemaker failure. Some patients rely on the function of pacemakers to survive. If the pacemaker does not work under a magnetic field, the patient may be at risk of cardiac arrest. Metal foreign bodies in the eyeball are important absolute contraindications
2. Relative contraindications for magnetic resonance imaging, such as coronary stents, joint metal replacement, and porcelain veneers, need to be analyzed based on the specific material conditions, and the doctor should be informed to evaluate whether an MRI examination can be performed.
3. During the examination, remove any metal objects from the body, such as mobile phones, bank cards, lighters, etc., and do not bring them into the MRI room. Women's metal jewelry must be removed and cannot be brought into the MRI room.
4. Female patients should pay attention to the presence of intrauterine devices (IUDs) and inform staff that metal IUDs are not suitable for magnetic resonance imaging (MRI) examination, as they can easily cause the IUD to shift.
If it is necessary to scan the abdomen, it is required to fast for 4-6 hours the day before the examination to avoid the formation of gas from food staying in the intestines, which may cause artifacts and interfere with the examination results.
6. Pregnant women should try to avoid examinations as much as possible, even if magnetic resonance imaging (MRI) does not emit radiation. However, due to the special nature of the pregnant woman's body, the electric waves emitted by the magnetic field during MRI examination can easily affect the fetus. Therefore, it is necessary to avoid or communicate with the doctor in advance about the examination matters.
7. During the examination process, patients must strictly restrain themselves, so patients with confusion and claustrophobia are not suitable for magnetic resonance imaging.
In summary, the clinical application of magnetic resonance imaging (MRI) is becoming increasingly common. However, MRI requires a longer time, and patients must have sufficient patience and cooperate with doctors to pay attention to relevant examination precautions in order to ensure the accuracy of the results.