Magnetic Resonance Imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body. In many cases MRI gives different information about structures in the body than can be seen with an X-ray, ultrasound, or computed tomography (CT) scan. MRI also may show problems that cannot be seen with other imaging methods.
For an MRI test, the area of the body being studied is placed inside a special machine that contains a strong magnet. Pictures from an MRI scan are digital images that can be saved and stored on a computer for more study. The images also can be reviewed remotely, such as in a clinic or an operating room. In some cases, contrast material may be used during the MRI scan to show certain structures more clearly.
MRI is a non-invasive procedure, and there are no known side or after effects. The procedure is used for all parts of the body. The procedure is painless in fact you won’t feel anything. A faint knocking sound will be heard, which is simply the imaging process in operation.
The MRI procedure will last anywhere from 30 to 45 minutes, depending on the study requested by your physician. To conduct the MRI study, a technologist will assist you onto a padded, moveable scanning table. The magnet is open on both sides and the technologist will easily see you at all times.
During the exam it is important that you remain still. During the scan, you will not experience anything unusual. There is a faint knocking sound, which represents the magnetic field. After the exam you may resume all normal activities.
Depending on the study ordered by your physician, some MRI exams require the injection of a contrast agent called Gadolinium. Gadolinium is an organic compound and does not contain iodine. This is only used when the radiologist and/or referring physician have determined that it is necessary for diagnostic purposes. Gadolinium contrast highlights specific organs, blood vessels or tissue to better show the presence of disease or injury. This is injected into a vein in your arm.
Most people will not need sedation. If it is determined to be necessary, we may contact your physician who ordered this exam. You should not operate a motorized vehicle for the remainder of the day if sedation is used.
Special preparation is not required for most MRI exams. If you are having a MRI of the abdomen you will be asked not to eat or drink 4 hours prior to the exam. Continue to take medication prescribed by your doctor unless otherwise directed.
In preparation for your MRI you may be asked to remove make-up and dentures depending on the study. In some cases, you may also be asked to wear a hospital gown to avoid magnetic interference from fabrics, belt buckles and zippers.
Once you are situated on the table, make sure you are comfortable so that it is easy to keep still. Breathe normally. There is nothing about the procedure to make you uncomfortable. Once the exam is over, the technologist will assist you out of the scan room.
MRI imaging involves the use of a strong magnetic field. This magnetic field pulls on many metal objects.
Patients with pacemakers or neuro-stimulators cannot have an MRI. Patients who have had an incident of metal in their eye will need X-rays taken of their eyes prior to the MRI to make sure no metal remains in eye.
MRI Scans may not be conducted on people with cardiac pacemakers, defibrillators and stimulators, some types of aneurysm clips in the brain, some types of heart valves and some types of metallic implants. Please let your doctor know if you have had surgery involving the implantation of any metal, electronic or mechanical devices.
While continuing research indicates the safety of MRI during pregnancy, it is important to let your doctor and technologist know if you are pregnant or suspect that you are.