MRI scan

The abbreviation MRI stands for Magnetic Resonance Imaging. With this imaging technique, a scanner visualizes the joints, muscles, tendons, nerves, brain, and organs. This is done by creating a series of cross-sectional images ('slices'). By scanning a different slice each time, you get a complete picture of the body (or body part).

A strong magnetic field, combined with radio waves, ensures that different body tissues are clearly visualized. It is good to know that this involves non-harmful radiation.

By detecting the alternating vibrations (resonance) of hydrogen particles, the device forms an image of the tissue. The more water a particular organ or body part contains, the whiter the image. An organ such as the lungs, which contain little to no fluid, appears black.

The examination

During the examination, the patient lies on a narrow bed that slides into the MRI scanner. The scanner is shaped like a narrow tunnel. For people who cannot tolerate confined spaces (claustrophobia), or for people with (severe) overweight, this can be a problem. For these people, there is also an open MRI scanner, which eliminates these problems.

Once in the tunnel, it is important to remain still; otherwise, the images will not be sharp. The scanner itself is noisy; headphones with music and earplugs help to dampen the sound. The patient is given a call button that can be used if needed. The person operating the MRI scanner is in another room but can communicate with the patient via a microphone.

What to bring and what not to bring during an MRI

Because a strong magnetic field is present in and around the scanner, no metal objects are allowed nearby. Think of piercings, jewelry, zippers, and buttons. Wear comfortable clothing that contains no metal. Metal-free clothing is always available; feel free to ask for it before you enter the MRI scanner.

People with, for example, a pacemaker or a metal splinter in the eye cannot undergo an MRI scan. A possible pregnancy may prevent an MRI scan from being performed. It is therefore important to consider this in advance. Before the scan is performed, a questionnaire must be completed to determine whether someone may enter the MRI scanner.

Result of the MRI scan

Virtually all body tissues can be examined with an MRI scan, unlike an X-ray. After the scan, the images are on the computer. You can then scroll through the body step by step to see where the problem is.

Conditions that are clearly visible on an MRI scan include:

• Tears of the cruciate ligaments or meniscus of the knee
• Muscle tears
• Herniated discs
• Inflammation of the bowel
• Problems in the brain

How long does an MRI take?

Making an MRI scan normally takes between 15 and 45 minutes, depending on the number of images. It takes longer when a larger area is scanned. Fasting is not necessary for this examination. A radiologist reviews the images and prepares a report. The result is communicated later by the treating physician.