What does magnetic head vibration check?

Question 1: What diseases can brain magnetic resonance imaging detect mainly in the following aspects? I hope it will help you.

1, MRI of brain and spinal cord is more sensitive than CT in the diagnosis of brain tumors, encephalitis, white matter lesions, cerebral infarction and brain congenital abnormalities, and can find early lesions and locate them more accurately. The lesions of skull base and brain stem can be displayed more clearly because there are no artifacts. MRI can display cerebral vessels without using contrast agent, and find out whether there are aneurysms and arteriovenous malformations. MRI can also directly show some cranial nerves, and can find early lesions on these nerves. MRI can directly display the whole picture of the spinal cord, and has important diagnostic value for spinal cord tumor's or intraspinal tumors, white matter lesions of the spinal cord, syringomyelia and spinal cord injury. MRI can show degeneration, protrusion or protrusion of intervertebral disc lesions. It shows that spinal stenosis is also good. For cervical vertebrae and thoracic vertebrae, CT is often unsatisfactory, while MRI is clear. In addition, MRI is also very sensitive to display spinal metastases.

2. MRI of the head and neck well shows the tumor lesions of the eye, ear, nose and throat, such as the invasion of nasopharyngeal carcinoma on the skull base and cranial nerves. MRI is more clear and accurate than CT. Magnetic resonance imaging can also be used in cervical angiography to show vascular abnormalities. MRI can also show the range and characteristics of cervical masses to help identify them.

Question 2: What is the difference between head CT and MRI? Both of them are the most important imaging methods for brain lesions at present. But each has its own advantages and complements each other. CT examination is very fast, and it is most sensitive to acute cerebral hemorrhage and intracranial calcification, but it is not easy to show acute cerebral infarction within 24 hours. However, MRI is sensitive to hyperacute cerebral infarction and subacute cerebral hemorrhage within a few hours. Magnetic resonance imaging (MRI) is widely used in the examination of brain diseases and other parts because of its very high soft tissue resolution. The disadvantage of nuclear magnetic resonance is that it takes a long time to check. If there are ferromagnetic substances in the body, it is a taboo. Suggestion: CT and MRI are devices applied to human body examination based on completely different physical principles. Both of them are the most important imaging methods for brain lesions at present. But each has its own advantages and complements each other. CT examination is very fast, and it is most sensitive to acute cerebral hemorrhage and intracranial calcification, but it is not easy to show acute cerebral infarction within 24 hours. However, MRI is sensitive to hyperacute cerebral infarction and subacute cerebral hemorrhage within a few hours. Magnetic resonance imaging (MRI) is widely used in the examination of brain diseases and other parts because of its very high soft tissue resolution. The disadvantage of nuclear magnetic resonance is that it takes a long time to check. If there are ferromagnetic substances in the body, it is a taboo.

Question 3: What should be checked for skull magnetic vibration? 1. Magnetic resonance imaging of skull can examine vascular diseases, such as cerebral ischemia, cerebral infarction, cerebral hemorrhage and vascular malformation. 2. Can check tumor lesions, such as benign cysts, pituitary tumors, meningiomas; Malignant, glioma, brain metastasis, etc. ; 3. Can check the head trauma, such as brain contusion and laceration; 4. Can check sinus space occupying and sinusitis;

Question 4: What problems can magnetic resonance imaging (MRI) of the brain detect? Recently, more and more people use MRI without free radiation for health examination. What is magnetic resonance imaging? What diseases can it detect? Nuclear magnetic resonance photography is represented by a magnetic core, which is either radiation (that is, non-ionizing radiation, that is, radiation that does not dissociate the molecules in the body and is harmless to the human body), or a heavy and large magnet is placed in the nuclear magnetic resonance camera, which weakly but powerfully emits tens of thousands of times the intensity of the earth's magnetic field (nuclear magnetic resonance photography commonly used in clinic, its magnetic field is 30,000 times that of the earth). Magnetic resonance photography (MRI) is often used to examine various parts and organs of the body, and can be applied to every part of the whole body from head to toe. Imaging techniques can be used to check for structural or blood flow abnormalities. You can see through the patient's body, scan it carefully, and even see the fetus in the mother's belly clearly. However, the technology used in the exam is still in its infancy. Magnetic resonance photography can clearly see the amount of soft tissue and water in the body, and it has distinct layers, which is different from X-ray examination and computed tomography. Nuclear magnetic resonance photography can see the outermost skin to spinal nerves and obvious structures, but in the images of computed tomography, these structures, such as muscles, bones, nerve tissue, fat and water, are indistinguishable. Magnetic resonance imaging (MRI) can also clearly show the intervertebral disc and nerve roots between the bones of the spine and the pathological relationship between them, which can provide correct diagnosis. Acoustic neuroma grows between bone and brain tissue, and magnetic resonance imaging can clearly visualize it. It is not easy to see the lesion and its surrounding tissues if it is examined by computerized tomography. In addition, some tumors are metastatic from carcinoma in situ, and MRI is also easier to find early metastasis. MRI can also find many brain problems with unknown causes, such as abnormal development of cerebral cortex or myelitis at the end of brain (symptoms, treatment, prevention, common sense) in patients with multiple sclerosis. The invention of magnetic resonance imaging (MRI) is a great progress in medicine, many of which cannot be found by X-ray and computed tomography. Under magnetic resonance imaging (MRI), they all appear one by one, which makes doctors more capable of treating the real cause. Compared with computed tomography, MRI has increased a lot in sensitivity and accuracy, and the image clarity is 20 times that of computed tomography. So when should I do an MRI? Doctors will judge when to do MRI according to the clinical symptoms of patients. Not every case needs MRI, only when X-rays, ultrasound and computed tomography are useless. The large magnet of nuclear magnetic resonance is placed in a tunnel with a width of about 50~60 cm and a length of about 1 m, and its magnetic field will have an impact. Once the protons are arranged in sequence, electromagnetic waves are added outside the body to vibrate with the protons in the body. When the applied electromagnetic waves stop, the human body will release electric waves. The degree of "discharge" of tissues in different parts will be different, so the image signals presented will be different. The magnitude of the magnetic field is calculated in Tesla (t). The bigger the magnetic field, the stronger the signal, and the more subtle changes in the body can be seen. At present, most of the magnetic resonance photography used in clinical diagnosis is 1.5T, which is a kind of nuclear magnetic resonance specially used for research purposes. The weight of the magnet can reach 10, ranging from several tons to hundreds of thousands of tons. Because of nuclear magnetic resonance photography, its magnetic field is 30 thousand times that of the earth, and it has super magnetic force, just like a super big magnet. Therefore, in order to be safe, in addition to avoiding carrying metal into the magnetic field, people who have metal objects in their bodies, such as pacemakers, brain metal clips, fractures (symptoms, treatment, prevention, common sense, or iron filings in their eyes, are not allowed to do MRI. In addition, women in early pregnancy should also avoid MRI. Although MRI can detect many pathological conditions in the body, it still has limitations. For example, MRI cannot be used for bone examination because the bone is a dark piece in the film. If you want to see bone fragments such as calcification or trauma, you still need to use computer tomography to check. However, this shortcoming can sometimes be exploited. For example, the bone part is black because it does not display the signal, so once the signal is displayed, it means that it is abnormal and there is something wrong with the bone; If ordinary lung cancer (symptoms, treatment, prevention, common sense) metastasizes to the spine, it will. & gt