A technique that uses radio waves and magnetic field to create detailed images of the tissues and organs of your body is called magnetic resonance imaging or MRI.
MRI machines are large and tube-shaped magnets. The magnetic field temporarily realigns hydrogen atoms in your body as you lie inside an MRI machine.
The radio waves can cause the aligned atoms to produce very faint signals that are used to create cross-sectional MRI images. This machine can also be used to produce 3-D images.
Here are the most common reasons to undergo an MRI procedure.
MRI is a noninvasive way for your doctor to examine your tissues, organs, and skeletal system. It produces high-resolution images that help diagnose a variety of problems.
MRI is used in the spinal cord and brain to help diagnose:
This can also be used in blood vessels and heart to assess:
- Thickness and movement of the walls of the heart.
- The size and function of the heart’s chambers.
- Blockages or inflammation in the blood vessels.
- Structural problems in the aorta such as dissections and aneurysms.
- The extent of damage caused by heart disease or heart attack.
MRI can be used to check for tumors or other abnormalities of many organs such as:
MRI can be used to evaluate:
- Bone infections
- Joint disorders such as arthritis
- Tumors of the soft tissues and bones
- Disk abnormalities in the spine
- Joint abnormalities caused by traumatic or repetitive injuries
MRI may be used in addition to mammography to detect breast cancer.
Along with undergoing MRI comes potential risks.
Tell the technologist of you to have any electronic devices or metals in your body such as:
- Artificial heart valves
- Metallic joint prosthesis
- A pacemaker
- An implantable heart defibrillator
- Metal chips
- A shrapnel, bullet or any other type of metal fragment
- Cochlear implants
Your doctor will suggest an alternative exam or postpone the MRI if you are pregnant. Talk to your doctor if you have a liver or kidney problems because they light to limit the use of injected contrast agents.
Read on to learn more about what to expect before, during, and after your MRI scan.
Your doctor will ask you to lie down on a movable table that will slide through the MRI machine that looks like a tube with both ends open while a technologist will monitor you from another room. The MRI machine will create a strong magnetic field around you and radio waves will be directed at your body.
You will not feel the magnetic field or radio waves, and there are no moving parts around you because the procedure is painless. The internal part of the magnet produces repetitive tapping, thumping and other noises during the MRI scan. To help block the noise you can ask for music or earplugs. You may be given sedative before the scan if you are claustrophobic inside the MRI machine.
In some people, a contrast material, typically gadolinium may be injected through an intravenous (IV) line into a vein in your hand or arm and this will enhance the appearance of certain details. This procedure will take up about an hour or more.
To prevent blur in the images you must hold still. You may be asked to perform a number of small tasks such as answering simple questions, rubbing a block of sandpaper or tapping your thumb against your fingers. This helps pinpoint the portions of your brain that control these actions. You can return to your normal activities after the procedure.
A radiologist who specializes in interpreting MRIs will check and analyze the resulting images from your scan and will report his findings to your doctor, so you and your doctor can discuss the results of the MRI.