MRI is a way to look inside the body without using x-ray. MRI can produce two- or three-dimensional images of the inside of the body by using a large magnet, radio waves and a computer. The magnet is large enough to surround the patient.
Why is MRI important?
It is important because it can lead to early detection and treatment of disease. MRI pictures are extremely precise and doctors can often get as much information from MRI as they would from looking directly at tissue. MRI uses no x-ray, and the magnetic fields are not known to be harmful.
Preparing for the exam:
What should I wear to my appointment?
You should wear loose comfortable clothing. Avoid wearing clothes with metal/plastic button and zippers. Women are encouraged to wear a bra without metal snaps/hooks or under wire. If you do arrive wearing any of the above, you will be asked to change into a hospital gown or remove any articles of clothing that might interfere with your exam. You will need to remove your watch, wallet and metal items that can be damaged by the magnet or that can affect the exam results.
Before the exam:
You will be asked about your medical history. You will be told about the scanning procedure and you will be asked to sign a consent form.
You will have to remove any metallic objects, such as jewelry, hairpins, glasses, wigs, wallets and non-permanent dentures that can be damaged by the magnet. People with cardiac pacemakers and/or other implanted stimulatory devices can not have a MRI scan. We may not scan people with some types of metal implants, including some plates, clips, staples or sutures. If you have had any surgery, you must inform us.
You may be injected with a contrast agent depending on the type of exam that is ordered. This helps the radiologist distinguish between different types of tissues and anatomy within your body.
If you are pregnant, or think you may be pregnant, please advise the MRI technologist.
The technologist will help you onto the scanning table and can address any questions or concerns. You will be given a call bulb and will be positioned comfortably, generally with your arms at your sides.
As the scan begins:
The scanning table, which is simply a nonmagnetic stretcher, will slide into the giant magnet. Most of your body may slide through the magnet. Some exams require you to lie with your feet going into the scanner first and some with your head first. This position will depend on what part of your body we will be scanning.
During the scan:
Most patients do not feel anything during their exam, although some patients may feel some nerve stimulation (muscle twitches) or may feel warmer than when the exam started. You will hear some peculiar noises:
- The hum of the machine.
- A thump when the radio waves are turned on and off.
- Whirring, grating, or simply a loud knocking noise!
- You might also feel the vibration of the machine.
This is when the machine is acquiring images.
The technologist will be in speaking with you periodically during the entire study. If you need them at any other time you can squeeze the patient call bulb. It is very important to not move during the scan, as MRI imaging is very motion sensitive.
Total scanning time usually ranges form 30 – 90 minutes.
After the exam:
After the exam is completed, you will be able to go home and return to normal activities. The scan will be read by a radiologist. Your results will be given to you by your physician.