MRI of the heart - Causes, Symptoms and Treatment .MF .
In recent decades, scientists committed considerable advances in the diagnosis of diseases.However, in spite of the entire arsenal of available methods of examination of patients, often found difficult and controversial cases in which the diagnosis can neither deny nor confirm.Then the doctor may resort to highly informative methods of research, to which the magnetic - resonance imaging (MRI).On what is based the method?
In 1973, a scientist - a chemist Paul Lauterbur first published scientific work on the possibility of registration by means of computer systems, image obtained as a result of "capture" tomograph energy released by hydrogen atoms (protons).American scientist RV Damadyan in 1974 for the first time noted the differences in the radiation energy protons healthy and tumor tissues.In subsequent years, the improvement of the method was carried out.In Russia, a leading role in these achievements belongs scientist Ivanov VA
Magnetic - resonance imaging is based on the ability of protons releas
Currently, along with the study of the brain and spinal cord, spine, joints, internal organs, used magnetic - resonance imaging of the heart and coronary vessels.Common features of the method are reduced to the production of high-precision layering images of the internal structures of the heart valves and the movement of blood in the cavity of the heart and blood vessels.Also carried with cardiac MRI contrast agent, is injected into the bloodstream when the contrast agent (usually a gadolinium), falling into the coronary arteries and the heart chamber, thus enhancing the "visibility" vessels.This method is called the magnetic - resonance angiography.
Advantages of the method lies in the fact that it is not invasive (no penetration into the tissue), informative, safe, can be carried out repeatedly, does not bear the radial load (as it does not use the energy of X-rays, in contrast to CT).
Disadvantages of the method include the high cost of research.This is due to the fact that the clinic in the procurement of such complex technical devices like scanner, spends a lot of money not just to the purchase of equipment, but even for its maintenance, equipment cabinet, payment for electricity and so on. D.
Indications forcardiac MRI MRI
appointed in cases where the rest of the heart imaging techniques (ultrasound of the heart) and blood vessels (angiography) does not allow to specify the diagnosis.Appointed with suspected unconfirmed by other methods of disease, such as:
1. Heart disease
heart tumor - a tumor of the mediastinum with a view to determine the extent of tumor invasion into the heart tissue
- complex congenital heart
- acquired heart defects
- complicatedmyocardial infarction - the gap ventricular wall, aneurysm ventricular rupture, blood clots in the cavity
heart - cardiomyopathy, hypertrophy
infarction - arrhythmogenic right ventricular dysplasia
- coronary heart disease to assess the patency of the coronary arteries when coronary angiography (invasive method of testing) is contraindicated
-abnormalities of structure and aneurysms of the coronary arteries occlusion (blockage) aortic - coronary bypass grafts
- differential diagnosis of ischemia and myocardial infarction (estimated viability and myocardial contractility)
- pericarditis - inflammation of the outer
lining of the heart - the control of medical or surgical treatment of heart diseases, such as, offset implanted occluder closure defect atrial and ventricular septal.
2. aorta and pulmonary artery disease
- congenital vascular structure (coarctation of the aorta, aortic valve defects, and pulmonary embolism, arterial canal open)
- dissecting aortic aneurysm
- pulmonary embolism
Contraindications Cardiac MRI
Whilethat holding heart imaging is completely safe for the patient, the method has some limitations.Contraindications include:
- the presence of metal implants in the body - occluders, stents (it is recommended to carry out research not earlier than 1.5 - 2 months after surgery), intracardiac catheters and electrodes, clips in the cranial cavity, pacemakers and cardioverter - defibrillators, hearing aidsand implants in the middle ear cavity, cava - filters.Failure to conduct MRI for these structures because the metallic material can deform not only because of its image of magnetic properties, but may still heat up and cause the displacement of the implant with the loss of its function.Exceptions are implants made of titanium, as it is not ferromagnetic.When the artificial valve prostheses examination can be carried out, but dentures can cause artifacts in the image, thereby reducing the information content.In each case, the possibility of MRI determined by the physician individually, taking into account all the indications and contraindications.
In addition, MRI is not recommended in conditions such as:
- 1 trimester
- psychiatric disorders (agitation, panic attack)
- alcohol or drugs
- extremely serious condition of the patient with the need to control and support the vitalfeatures (mechanical ventilation, continuous ECG monitoring)
- severe renal and hepatic failure for cardiac MRI with contrast as the contrast excreted by the kidneys and can affect the original changes in the liver (in the absence of organ failure contrast is absolutely safe)
- claustrophobia (in this case, to conduct research in an open MRI scanner, without placing in a closed tunnel tomograph)
preparing for a patient to MRI
special training before the test is not required.You can drink water and take small portions of food.Before entering the study you must remove all metal objects from your body (necklaces, earrings, other jewelry).In the presence of implants in the body of any patient must inform the doctor.
How is MRI of the heart?
survey may be carried out in a clinic or in a hospital.The patient before the study comes to the separation of X-ray diagnostics, and he was invited to the office.A doctor holds a conversation with him, and then visually examining a patient for the presence of scarring after surgery for implantation of metal devices.Next, the patient is offered to change into a comfortable shirt and lie on the couch, which is connected with the tunnel scanner.During operation, the imager creates sufficiently intense audible noise caused by operation of the magnet and RF coils.To reduce unpleasant subjective sensations in connection with noise patient suggests using headphones.Work equipment operates with the remote doctor from an adjacent cabinet, and so that the patient was able to inform the doctor about increasing discomfort in the tomograph has a button, which can push the patient.If you are planning the introduction of a contrast agent, cardiac MRI is performed before and after contrast.Contrast is administered intravenously after allergoproby.All study takes 20 to 50 minutes, sometimes longer.After the end of the imager to the patient offer to get out of the office, change his clothes and expected results and escorted him to the police station where he is being treated.At this time, the doctor evaluates the series of images and gives a conclusion.
Explanation Cardiac MRI results
heart tomogram and blood vessels
As a result of examination the doctor evaluates the anatomical structure of the heart and blood vessels, the volume of the heart chambers, valves motion and blood to cells, contractility of individual sections of the myocardium, the presence of areas of damage or ischemiainfarction, scarring or inflammation in heart tissue, the presence or absence of tumor lesions of the heart, and the integrity of the partition walls of the atria and ventricles.Contrast vessels can reveal abnormalities of their structure, permeability and degree of atherosclerosis lesions or absence of these signs.Interpretation of the results can only be done physician radiologist, past specialized in magnetic - resonance imaging, any independent assessment of the patient to enter into unacceptable.The patient will need to provide the resulting conclusion, doctor, appoint a survey.
complications during heart MRI without contrast does not arise.When intravenous contrast may develop nausea, vomiting, allergic reactions, angioedema, anaphylactic shock.Prevention is the thorough collection allergoanamneza.For emergency treatment in these situations cabinet equipped with antishock set.
therapists Sazykina OJ