Magnetic resonance imaging of the brain
This type of research as magnetic resonance imaging of the brain, also known as MRI, or MRI, is currently one of the most reliable types of tomographic studies of the causes and manifestations of various diseases. It can help how to install a variety of abnormalities in development and functioning of the organs, and to observe the functioning of the organism in real time. The most frequent and efficient this method is used when
- Vascular diseases of the brain – hemorrhagic stroke, heart attack
- Demyelinating diseases – acute disseminated encephalomyelitis, multiple sclerosis
- Formations in nerve ganglions and brain in General, meningioma, pituitary adenoma, neurinoma, as well as the effects of various injuries
The principle of MRI is based on nuclear magnetic resonance – the physical phenomenon in which the hydrogen atoms respond to the electromagnetic waves.
The brain is literally the most important and most difficult diagnosis and treatment of the human body due to characteristics of its location and structure. If most of the other systems is the ability to easily handle, transplant and even to implant artificial organs, any brain surgery is a huge risk.
For informative and accurate diagnostic method was needed that would look at the processes occurring inside the skull, without damaging it. Since the symptoms in most diseases related to the brain is headache, dizziness and nausea, impaired vision, it is impossible to make an accurate diagnosis only on them, not knowing the overall picture of what is happening.
Using tomography, it is possible to create a full picture with high resolution everything that happens with the spinal cord and the brain and other body systems. Measurement of the velocity of blood flow, the current of fluid in the spinal canal, the presence and degree of diffusion of the tissue, the activity of the cerebral cortex when different stimuli (this method is called functional MRI) it is possible to measure and monitor.
This research method was almost simultaneously invented in the West and in Russia. In our country it was originally called NMR – nuclear magnetic resonance, but later, after the Chernobyl tragedy, he was replaced by MRI as the population had developed radiophobia – fear of radiation in any form. In the new term there was no mention of "cores", so he was perceived by patients positive, despite the fact that the principle has not changed. However, some experts still use firstversion of the name method, but this does not appear no error.
But what's the image quality? Initially, CT had a relatively low induction magnetic field, but because the pictures were fuzzy and not too informative. Today, to create a MRI used powerful neodymium permanent magnets and superconductors that work at liquid helium. In the first case, when using permanent neodymium magnets, the electromagnetic field is weaker and slightly worse diagnosis, but the unit itself may be of open type – that is, at the doctor during the study have access to the patient, but can carry out the manipulation, and the patient may, for example, stand or move. Such a study was called interventional MRI. In the second apparatus is closed, but the obtained data clearly illustrate all the necessary parameters.
Today was possible the last step in diagnostics – computer 3D modeling of the body in different slices, made in real time through the study of magnetic resonance imaging. As a result, virtual endoscopy used in the diagnosis of various systems of the human body.
Medical equipment and MRI
For various reasons the use of medical equipment during use of the MRI is severely restricted. Generated by the magnets, the electromagnetic field may adversely affect the operation of medical equipment and implants in the human body. Therefore, there are special devices with a marking MR in the triangle – for example, artificial lung ventilation, which is approved for use in the area of imaging. Unfortunately, this apparatus is not yet so perfect as those that are forbidden because of the abundance of them in electronic "stuffing", but adequately cope with their functions. Naturally, with this for open and tunnel scanners use different devices.
Contraindications to magnetic resonance imaging
Unfortunately, the features of MRI imposes severe restrictions on some groups of patients. The presence of a certain medical equipment, certain types of medication, the patient's condition, both physical and psychological, create absolute and relative contraindications.
The conditions under which conduct magnetic resonance imaging is strictly prohibited:
- Established patient ferromagnetic Ilizarov
- Established patient electronic or ferromagnetic implant middle ear
- Any established patient with a large metal implant or the presence in the body of ferromagnetic debris
- Established patientpacemaker
The conditions in which MRI may be prohibited and mandatory pre-consultation:
- Established patient non-ferromagnetic implant in the inner ear
- Established patient a cochlear implant to the inner ear
- Established patient a prosthetic heart valve
- Established patient an insulin pump
- Established patient nerve stimulator
- Established patient hemostatic clips
- The patient has decompensated heart failure
- The patient claustrophobia in any form
- The patient has tattoos that were made with paint with a content of compounds of metallov
- Finding the patient in the first trimester of pregnancy
- Finding the patient in a poor condition.
- Finding the patient in serious or critical condition for any disease
It should be noted that the prostheses made of titanium are not ferromagnetic and patients admitted to the study. However, if titanium compounds contained in the paint, which were made tattoo, contraindication remains in force – the fact that because of the strong electromagnetic field at the location of the tattoo can develop severe burns.
Indications for study by MRI
There are several types of MRI of the head, each of them has its group indications.
Brain MRI for a child
Unfortunately, when conducting magnetic resonance imaging of the head, the child raises many problems, because of which not every hospital is ready to accept young patients. Most often the problem is fear – the kid finds himself alone in a tunnel, where there is something unclear and thus need to lie still. Therefore, diagnosis often exhibit special requirements for minors or patients are ready to accept them only after a personal talk. Often in labs imaging is contraindicated for children up to seven years, but it not caused by influence of electromagnetic field on the child's body, namely the behavior of children during the study.
How to prepare for imaging
Most importantly, care of the patient before the procedure – what will happen internally and how it should be prepared. Most often, doctors are kindly requested to dress in light clothing without metal details and decorations, or better yet in a hospital gown.
Regarding limitations in food and drink, forbidden alcohol before the study – otherwise the patient can adhere to your usual diet, as it practically does not affect the results of the MRI of the brain. If any special requirements forspecific case the doctor must notify the.
If the patient is allergic to iodine or other contrast material for intravenous studies, should inform the property in advance. In principle, it is necessary to report all of your possible allergic reactions and whether the patient has asthma.
Naturally, the doctor and nurse need to report all illnesses and operations that are present in a patient was recently transferred. For example, renal disease makes it impossible for a contrast MRI study, but this detail must be known to the doctors beforehand and not when the patient is ready to be placed in the machine.
Women should be required to warn the doctor about possible pregnancy. Despite the fact that since the opening of the MRI method and to date has not revealed any impact on the fetus, in medical practice it is customary to refuse patients in the study during pregnancy.
Naturally, be sure to remove all jewelry, empty your pockets, if they have to remove the piercing. Any metal object during the study is the risk for the patient to stay with serious burns.
In addition, your doctor may offer the patient earplugs and sedatives in case he suffers from panic attacks and claustrophobia. Children are given earplugs mandatory.