When you receive magnetic resonance imaging — an MRI — in Eau Claire, a magnetic field and radio waves are used to create detailed images of the organs and tissues within your body. It produces high-resolution images that help diagnose a variety of problems. A cardiac MRI provides still or moving pictures of how the blood is flowing through the heart and detects irregularities, and often is used to diagnose pulmonary valve disease.

Most MRI machines are large, tube-shaped magnets. When you lie inside an MRI machine, the magnetic field temporarily realigns hydrogen atoms in your body. Radio waves cause these aligned atoms to produce very faint signals, which are used to create cross-sectional MRI images — like slices in a loaf of bread.

DURING AN MRI

The MRI machine looks like a tube that has both ends open. You will lie down on a movable table that slides into the opening of the tube. A technologist monitors you from another room and you can talk with that person by microphone.

The MRI machine creates a strong magnetic field around you, and radio waves are directed at your body. The procedure is painless. You don't feel the magnetic field or radio waves, and there are no moving parts around you.

During the MRI scan, the internal part of the magnet produces repetitive tapping, thumping and other noises. If you are worried about feeling claustrophobic inside the MRI machine, talk to your doctor beforehand. You may receive a sedative before the scan.

In some cases, a contrast material, typically gadolinium, may be injected through an intravenous (IV) line into a vein in your hand or arm. The contrast material enhances the appearance of certain details.

An MRI can last up to an hour or more. You must hold very still because movement can blur the resulting images.

AFTER AN MRI

If you have not received a sedative before the scan, you may return to your normal routine immediately.