MRI - Magnetic Resonance Imaging

Magnetic Resonance Imaging (MRI) is a non-invasive procedure using magnetism and radio waves to provide detailed images of your body and its soft tissue structures. MRI's help diagnose your disease, monitor the progress of your treatment or help understand other medical situations that arise.

In most cases, there is no special preparation for an MRI scan. You can eat and drink normally on the day of the scan although it is best to avoid large amounts of coffee or other things that might make you restless.

Depending on what part of your body is being scanned, you might have to wear a gown, but usually you can wear regular clothes (without heavy metal attachments). Because of the strong magnetism, it is very important not to bring any metal into the scan room. You will be asked to remove your watch, keys, coins, earrings and anything else metallic.

For the actual procedure, you lie on your back on a movable scanning table that moves into the MRI scanner. Depending on what type of scan is necessary, the table moves you into the machine head or feet first. Once the body part to be scanned is in the exact center of the magnetic field, the scan begins.

Most young people have no trouble during the procedure but some feel claustrophobic. To make you more comfortable, the inside of the scanner is well lit, and has a fan that gently blows fresh air. Even though the technician is in another room during the procedure, he or she can see you at all times and you can see through a mirror positioned at eye level inside the machine. You can also talk to the technician through an intercom system. If you want, you can usually bring someone with you in the room (check with the technician first).

Most MRI scans take between 30 and 90 minutes. Your only job is to remain completely still because even slight movement can spoil the images. During the scan you will hear a variety of sounds such as humming and hammering. It may sound like the technician is hitting the side of the scanner with a large hammer. These sounds are normal. You may be given earplugs or stereo headphones to muffle the noise (in most MRI centers you can even bring your own cassette or CD). But don't be surprised if the music is drowned out by the noise.

Other than maybe being a little uncomfortable (and loud!), an MRI is completely painless and you should have no side effects to worry about.

CAT (or CT) Scan

CAT stands for Computerized Axial Tomography. (sometimes referred to as CT scans). CAT Scans combine x-rays and computers to produce very detailed cross sectional images of your body.

Depending on what part of your body is to be scanned, you may be given something called "contrast" to make things show up better on the scan. The contrast is given through an IV or if you are having an abdominal scan, you may have to drink it. It tastes really terrible but it's important. Just make sure it's cold and that you have a good "chaser" nearby - soda or juice.

The good thing about CT's is that they are quick but you need to lie very still to get a good scan. After the scan is done, it can be computer reconstructed to show three-dimensional images of the part of your body that was scanned.

Because the machine produces X-rays, the technician is in a separate room near the computer but can talk with you through an intercom. You will probably be alone in the room, unless you request that someone be with you. That person will need to wear a lead vest as protection against the x-rays.

Bone scans

Bone scans can show abnormalities long before they show up in x-rays, which is why your doctor probably ordered one. The radioactive compound is given through an IV and is absorbed by your bones as it travels through your body. You have to drink a lot of water or juice right after the isotope is injected to clear your body of radioactive material not absorbed by your bones.

The bone scan may take about an hour and you have to lie very still while the camera moves back and forth. You might be asked to change positions several times to get different images. Because no x-rays are emitted, you can have someone stay in the treatment room with you.

The radioactive material or tracer concentrates in areas where there is a lot of activity, so to speak - like normal growing bone or in bone tumors or bone infections. These areas will show up as "hot spots" on the scan.

Ultrasound

Ultrasound scans are images of your internal organs created by using sound waves. High frequency waves are directed at your body and then reflected (echoed) back to a scanner that creates an image of the area scanned.

A special gel is spread on the skin over the area to be examined. This helps to define the area as clearly as possible by enhancing the transmission and reception of the sound waves. The ultrasound scanner or transducer looks like a small paint roller that the technician moves over the area to be scanned. It is completely painless but the gel can sometimes feel a bit cold.

There is nothing special that you have to do to prepare for an ultrasound and there are no side effects.