Some of the common purposes for performing this cardiac MRI in radiology are to estimate the structure and function of the heart, valves and major arteries. To diagnose various heart problems or coronary heart diseases. After diagnosing; this test also helps to find out the best treatment for the patient. The images formed by using this test provides a clear picture of the heart so the physician can evaluate the size, thickness, and health of the heart and its various chambers and vessels. These prints help to find out the blockages in the arteries and also the percentage of blockage. The specialists are able to check that how much the heart has been affected by the attack and this test is also helpful to evaluate the recovery of the patient after treatment. Few precautions should be taken before taking this test in order to avoid serious problems. Before taking this test the patient is asked to wear loose dresses or they are sometimes provided with a gown but the dress should not contain any metal item with it. Sometimes there are some limitations in eating and drinking before taking this test but if such is the case the doctor will himself inform the patient otherwise the patient is allowed to take the daily routine stuff. In magnetic resonance imaging the patient has to either eat contrast material or to take an injection of contrast material. Gadolinium is the contrast material used during MRI test and it is iodine free so normally it does not cause any allergy like asthma, vomiting, fever and hives. The radiologist or the person who is conducting the test should ask the patient if he is having any kind of allergies or health problems like kidney problem or any surgery through which the patient has been undergone. In such conditions the test can not be taken using contrast material. If female patient is undergoing this test then they should be sure about their possibility of being pregnant because the affects of magnetic resonance imaging on the baby are unknown and can cause problems. If the patient is prone to anxiety, nausea or claustrophobia then he should inform the radiologist about it and they will be given a sedative drug for this i.e. a drug to calm and soothe. The doctor can also ask the patient to stop eating 6 hrs before the test in such cases. If the patient has fear of close or tightly packed spaces then he should inform the doctor. Nowadays there are some machines for MRI that are open and can be used for such patients. Jewellery items and other metal items are not allowed during the test so these should be removed before the test begins. These things are avoided just because metal can interfere with magnetic field. Things like jewellery, watches credit card and hearing equipment can be damaged so better to remove them. Items like hair pins, zippers, safety pins etc distort the images so the result would not be proper. Hence pens, eyeglasses, rings n other metal item should be removed before the patient enters into the testing room. Sometimes this test is safe for the patients having metallic implants but there are some limitations in this regard as well. There are some types of metallic implants that are not suitable for the test. Internal implants like defibrillator, ear implants, brain clips (aneurysms) and cardiac pacemakers can not be scanned through this process. Medical devices or electronic equipment are some times unsafe for this procedure. Devices like artificial heart valves, artificial limbs, pace makers, infusion catheter, nerve stimulators, pins, screws, plates, surgical staples and metallic joint prostheses are prone to risk. Severe injuries can be caused due to such devices. If there are brain clips then due to strong magnetic field these clips can move from there original places. The cardiac pacemakers and defibrillators can fail to function. Cochlear (small devices that are implanted to help the people who are not able to hear) implantations can get damaged. Tattoos contain iron that can get heat up during MRI. The doctor will guide the patient if he or she should have MRI in such cases or not or in some cases the patient has to go through an x-ray and show the result to the doctor so that the doctor can analyze the condition of internal implantations. Mostly before taking this test a screening form is given the patient to fill up. This form contains all the questions to get to know about the health conditions of the patient. This form asks the patient if he has undergone some sort of surgery or having any metallic object or implanted device in the body and after that the doctor is able to decide that they should proceed the procedure or not.
The cardiac magnetic resonance imaging is done by using MRI unit. MRI unit is quite large and cylindrical in shape. The whole unit is surrounded by a circular magnet. The patient will lie on the emanation table; this table is moveable and when the patient is on the table it will slide into the center of the magnet. There are some units that are not completely surrounded by magnets such units are known as short bore systems. There are units that are open from all sides such unit is called open MRI. These open MRI units are basically for the patients who are afraid of closed spaces. Latest open MRI units are very much developed; they can produce high quality images while open MRI units with older magnets can not produce such images. These units are located at any hospital or at any imaging laboratory. The workstation that is used to process the image after the test is situated in a different place outside the testing room. The procedure is usually 45 to 90 minutes long and it depends on the number of readings needed and with the latest equipment the test takes less time. The room where this test is conducted is constructed in such a way so as to prevent radio waves from disordering the machine and this room also prevents the magnetic field generated by the MRI unit from interfering with other accessories and equipment in the room and outside the room. It is a simple and painless procedure; the patient has to just lie on his back and the machine operator will operate the machine from other room but will be able to see the patient and can communicate with him using some intercom system. Headphones are provided during the test so as to lessen the noises made by the MRI machine. These noises are like humming, buzzing noises. Patient should not move during the test; he or she should remain still otherwise the images will be blurred. There are medicines that can be provided the patient before test to make him or her relax. The patient is asked to hold the breath for 10 to 15 minutes for taking the pictures of heart. Researches are being made in this area so as to allow the patients to take breath and still get the high quality images. After the test if the patient has not taken any relaxation medicine then they can return to their normal activities very soon after the test and if the patient has received some medicine then it takes some time to get back to the normal routine.
There are few benefits of MRI in radiology: it is a non invasive procedure and does not involve penetration and radiation exposure. This technique is much detailed than other imaging techniques and can produce much clear results due to this reason this technique and procedure is now the most reliable one for the diagnosis of heart problems. It is able to diagnosis different type of heart problems just in a single test; it includes diagnosis of artery disease, amount of damage done by the heart attack, heart failure, valve diseases, pericardial problems, cardiac tumors and so on. By analyzing the images the doctors can find out the areas of heart having poor blood supply or the areas of heart that are not moving properly. Normally angiography is the procedure that is used to find out the blockages in the arteries but researchers believe that soon this angiography will be replaced by the procedure of cardiac magnetic resonance imaging. It is because angiography involves iodine based dyes and it is invasive procedure so sometimes for some patients angiography can be harmful. Where as MRI does not need any kind of x-ray or iodine based dyes so it is safer than angiography. Magnetic resonance imaging can also detect the problems that are not easily detected by other imaging methods. It is a quick procedure as well as it provides the detailed images so the doctors are able to check out the structure as well as function of the heart.
Along with the benefits there are also some risks associated with the cardiac magnetic resonance imaging in radiology. Risks are involved in all the branches of medical but if the provided precautions are followed properly then these risks can be avoided. If drugs for the relaxation of the patient are being used then there is a risk of giving the drug in large quantity so this thing should be kept in mind that the quantity should not exceed and if by mistake it does exceed then the nurse should be able to deal with it. The equipment and machine should be functioning properly otherwise it can produce harm to the patient. There are very little chances of having some sort of reaction or allergy due to the dye that has been injected and if such reactions are caused then they are really mild and easy to handle. The dye can cause side effects like headache, nausea, dizziness, change in taste and allergy. This procedure has normally no side effects from magnetic fields and radio waves.
This procedure may take more time than other imaging techniques and it costs much than x-rays and CT scans. But it is a reliable and safe technique as it does not have any serious reactions or penetration. Researches are being made in this area to bring more and more reliability and easiness in this procedure.
http://www.nhlbi.nih.gov/health/dci/Diseases/mri/mri_whatis.html
