Head MRI. What?

Question 1: What diseases can be detected by brain MRI, mainly including 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 does the head MRI examine? 1. Magnetic resonance head can check vascular diseases, such as cerebral ischemia, cerebral infarction, cerebral hemorrhage, vascular malformation, etc. 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 brain MRI detect? Recently, more and more people use magnetic resonance imaging (MRI) without ionizing 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 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 vaguely but powerfully emits a force equivalent to tens of thousands of times the earth's magnetic field (generally used for clinical nuclear magnetic resonance photography, 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. Using imaging technology to check whether there is any structure or abnormal blood flow can see through the patient's body and do detailed scanning. Even the fetus in the mother's belly is clearly visible, but the technology used in the examination is still in its infancy. Magnetic resonance photography can clearly see the amount of soft tissue and water in the body, which is different from X-ray examination and computed tomography. Magnetic resonance photography can see the outermost skin to spinal nerves and well-defined structures, but in the images of computed tomography, these structures, such as muscle, bone, nerve tissue, fat and water, are indistinguishable. 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, which can be clearly displayed by MRI. If computed tomography is used, it is not easy to see the lesion and its surrounding tissues. In addition, some tumors have metastasized from carcinoma in situ, and it is easier to find early metastasis by magnetic resonance imaging. Magnetic resonance imaging can also find many unexplained brain problems, such as abnormal development of cerebral cortex, or myelitis at the end of the brain in patients with multiple sclerosis (symptoms, treatment, prevention, common sense). The invention of magnetic resonance photography is a great progress in medicine, and many tumors or lesions can not or are not easily found by X-ray and computed tomography. All these are shown in MRI, 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 we have an MRI? Doctors will judge when to do MRI according to the clinical symptoms of patients. Not every case needs MRI, only when X-ray, ultrasound and computed tomography are not available. The big magnet of nuclear magnetic resonance is placed in a tunnel about 50~60 cm wide and 1 m long. The magnetic field it emits will affect the protons in the hydrogen nucleus in the patient's body, so that protons in different directions of rotation will be obedient. Once the protons are arranged in sequence, electromagnetic waves are applied from the outside to make them resonate 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, the magnetic resonance used in clinical diagnosis is mostly 1.5T, and the magnetic resonance used in research is more than 3T. 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-large magnet. Therefore, in order to be safe, in addition to avoiding bringing metal into the magnetic field, as long as there are metal objects in the body, such as pacemakers, brain metal clips, steel left in the body for fracture (symptoms, treatment, prevention, common sense) surgery, etc. In addition, women should avoid MRI in early pregnancy. Although MRI can detect many pathological conditions inside the body, it still has its limitations, such as the examination of bones, because bones are dark in the film, and if you want to see bone calcification or bone fragments caused by trauma, you still need to use computer tomography. However, sometimes you can take advantage of this shortcoming, for example, because bones don't show signals. If ordinary lung cancer (symptoms, treatment, prevention, common sense) metastasizes to the spine, it will. & gt