What can a brain MRI scan detect?

The main purpose is to check for organic pathological changes. The nature of the disease can be determined for chronic organic cranial nerve damage. However, cranial nerve dysfunction is divided into functional and organic diseases, and it is difficult to fundamentally cure the disease if it is found to be organic. Functionality is different. With the right treatment, recovery or near recovery is possible.

Recently, more and more people are using magnetic resonance imaging without ionizing radiation for health examinations. What exactly is magnetic resonance imaging? What diseases can it detect? MRI uses magnetic nuclei to detect Manifestation, rather than radiation (that is, non-ionizing radiation, that is, radiation that does not ionize molecules in the body and is relatively harmless to the human body), that is, using a heavy and large magnet placed in an MRI machine , faintly but powerfully emit a force equivalent to tens of thousands of times the earth's magnetic field (the magnetic field of MRI generally used clinically is 30,000 times that of the earth). MRI is commonly used It can be used to check various parts of the body and organs. It can be applied to every part of the body from head to toe. It uses imaging technology to check whether there are structures or abnormal blood flow. It can see through the inside of the patient's body and do detailed scans. It is connected to the mother's abdomen. The fetuses are clearly visible, but the technology used in breast examination is still in its preliminary stages.

MRI photography can clearly see the amount of soft tissue and water in the body, and the layers are clear and different. For X-ray examination and computed tomography, MRI can see the outermost layer of skin to the nerves in the spine, and the structured structures, but in the images of computed tomography, these muscles, bones, and nerve tissues , structures such as fat and water are mixed together and cannot be distinguished. MRI photography can also clearly display the intervertebral discs and nerve roots between the bones of the spine, as well as the pathological relationship between them, and can provide a correct diagnosis. .Acoustic neuromas grow between bones and brain tissue, and magnetic resonance imaging can better visualize them. If computed tomography is used for examination, it is not easy to see the lesions and surrounding tissues. In addition, some tumors are caused by carcinoma in situ. Metastatic tumors can also be easily detected in the early stage of metastasis by MRI. MRI can also detect many previously unexplained brain problems, such as abnormal cerebral cortical development or multiple sclerosis. Myelin lesions on the patient's cranial nerve terminals, etc.

The invention of magnetic resonance imaging is a major advancement in medicine. Many diseases that could not or were not easily discovered by X-ray and computed tomography Tumors or lesions are revealed one by one under MRI, allowing doctors to better target the real cause of the disease. Compared with computed tomography, MRI is superior in sensitivity and accuracy. have increased a lot, and the image clarity is 20 times that of computed tomography.

How to perform MRI photography? Just lie down in a tunnel-like instrument and it will feel like you are in space. Like a cabin, as the examination proceeds, the instrument will make a noise like an earth drill. Then, the patient can close his eyes and relax, and perform this non-invasive examination in a relaxed mood.

So what? When should MRI be done? Doctors will judge when to do MRI based on the patient’s clinical symptoms. Not every case requires MRI, but after X-ray , only need to be used when ultrasound and computed tomography cannot be used.

The large magnet used in MRI is placed in a tunnel about 50 to 60 centimeters wide and more than 1 meter long. Inside, the magnetic field it emits will affect the protons in the hydrogen nuclei in the patient's body, causing the protons that originally rotated in different directions to rotate in the same direction; once the protons are arranged neatly, electromagnetic waves are added from outside the body to vibrate the protons in the body. , when the external electromagnetic waves stop, the body will release radio waves; the degree of "discharge" of the tissues in each part will be different, so the image signals presented will be different. The size of the magnetic field is measured in Tesla ( Tesla, T) is the calculation unit. The larger the magnetic field and the stronger the signal, the more subtle changes in the body can be seen. Currently, most of the MRIs used in clinical diagnosis are 1.5T, and MRIs specially designed for research purposes For nuclear magnetic resonance imaging, it is 3T or higher, and the weight of the magnet can reach more than 10 tons to hundreds of thousands of tons.

Due to nuclear magnetic resonance imaging, its magnetic field is 30,000 times that of the earth, and it has Super strong magnetism is like a super big magnet, so for safety reasons, in addition to avoiding carrying metal into the magnetic field area, as long as there are metal objects implanted in the body, such as cardiac pacemakers, metal clips on the brain, and steel plates left in the body during fracture surgery People who have nails or whose eyes are prone to iron filings are not allowed to undergo MRI examination. In addition, women in early pregnancy should also avoid MRI examination.

Although MRI examination is It can detect many pathological conditions inside the body, but there are still limitations. For example, MRI photography cannot be used to examine bones, because bones are dark on the film. If you want to see bone calcification or Bone fragments caused by trauma still need to be examined using computed tomography. However, this shortcoming can sometimes be exploited. For example, the bone part appears black because it does not display a signal. Therefore, once a signal is displayed, it indicates an abnormality, and there is a problem with the bone. ; For example, the detection of common lung cancer metastasis to the spine will rely on this feature of MRI.

At present, MRI is still constantly improving. In addition to enhancing its functions, it also Develop in the direction of making patients feel comfortable, such as increasing the width of the tunnel to avoid occlusion phobia, reducing noise, or allowing patients to listen to music or watch movies while undergoing examinations. In addition, due to the three major tools of medical imaging, Computed tomography (CT scanner), magnetic resonance imaging (MRI), and positron emission tomography (PET) each have their own advantages; computed tomography and magnetic resonance imaging mainly look at structural abnormalities. Positron radiation tomography examines functional abnormalities. Therefore, scientists are working hard to combine these advantages.