Some patients may require the injection of a dye into a vein this can help certain tissues to show up more clearly. The machine makes a banging noise while scanning which might be unpleasant. Since radiation is not used, it can be repeated without problems. The test is not painful, you can't feel it. There are no known dangers or side effects associated with an MRI scan. It takes between 15 and 90 minutes, depending on the body part being scanned and the number of images the doctor needs to capture. The scan is usually done as an outpatient procedure, which means that you can go home after the test. In cases of severe anxiety, patients can discuss whether a sedative medication is appropriate. You'll be given headphones to wear and be able to talk to the staff throughout the procedure. Patients are often anxious about feeling claustrophobic in the scanner, but radiographers are used to reassuring and supporting patients to stay relaxed and calm. In some cases, the doctor may place a frame over the body part being scanned, which can help to capture a higher-quality image. It's important to lie completely still during the scan. You'll lie on a motorised bed that moves inside the scanner, either head or feet first depending on the body part being scanned. You may be asked to wear a hospital gown, but if not, wear clothes without metal zips, fasteners, buttons, buckles and underwire. Since you're exposed to a powerful magnetic field during the MRI scan, it's important not to wear jewellery or any other metal objects – this includes watches, dentures, piercings, wigs, and hearing aids. After you arrive at the hospital, you may be asked to fill in a questionnaire about your health and medical history. On the day of your MRI scan, you should be able to eat, drink and take any medication as usual, unless you're advised otherwise. Assess congenital cardiovascular conditions and any changes to the heart occurring as a consequence of these conditions.Examine associated structures, such as the large blood vessels in the surrounding tissue – for example, to check for the build up of plaques.Assess damage occurring to the heart tissue after a heart attack or in association with valvular disease.Give very detailed imaging of the thickness and size of the chamber walls.Characterise tumours (as benign or malignant abnormal growths) and check their progression (if they have changed in size or spread to nearby tissues).Look for changes associated with bleeding or when the brain has been starved of oxygen after a stroke.An MRI scan of the brain and spinal cord can assess a multitude of different abnormalities, since it can provide clear pictures of these structures even though they are surrounded by bone tissue. The tissue that contains the least hydrogen atoms (such as bone) turns out dark, while tissue that has many hydrogen atoms, like fatty tissue, appears much brighter.īy changing the timing of the radio wave pulses, it's possible to gain information about the different types of tissues that are present. Therefore, almost all the protons within the body are affected by the strong magnetic field, and this allows detailed MRI images to be created.Īn MRI scan can be used to produce pictures of almost all the tissues in the body. Together with oxygen and carbon, hydrogen makes up 99 per cent of the human body. This strong magnetic field aligns particles called protons, which are found naturally within the body – mostly in hydrogen atoms. When the patient lies inside, radio waves 10,000 to 30,000 times stronger than the magnetic field of the earth are sent through the body. Read on to find out how the machine works, what an MRI scan shows, how it differs from a CT scan, and what to expect on the day: How does an MRI scan work?Īn MRI scanner is a large, cylinder-shaped magnet. If you've never had this scan before, the procedure is nothing to worry about. Using Magnetic Resonance Imaging, a doctor can create pictures of tissues, organs, and other bodily components and view them on a computer. An MRI scan is a safe, painless test that uses magnetic fields and radio waves to produce detailed images of the inside of your body.
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