Magnetic resonance imaging (MRI) is a technique that uses a magnetic field and radio waves to create detailed images of the organs and tissues within your body.
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.
The MRI machine can also be used to produce 3-D images that may be viewed from many different angles.
MRI is a noninvasive way for your doctor to examine your organs, tissues and skeletal system. It produces high-resolution images that help diagnose a variety of problems.
MRI is the most frequently used imaging test of the brain and spinal cord. It’s often performed to help diagnose:
An MRI may be used to check for tumors or other abnormalities of many organs in the body, including the:
MRI may be used to help evaluate:
The presence of metal in your body may be a safety hazard or affect a portion of the MRI image. Before receiving an MRI, tell the technologist if you have any metal or electronic devices in your body, such as:
Before you schedule an MRI, tell your doctor if you think you’re pregnant. The effects of magnetic fields on fetuses aren’t well understood. Your doctor may recommend choosing an alternative exam or postponing the MRI.
It’s also important to discuss any kidney or liver problems with your doctor and the technologist, because problems with these organs may limit the use of injected contrast agents during your scan.
Please leave your valuables at home, including jewelry, to prevent it from being lost or stolen, for they have to be removed prior to entering the scan room.
If you don’t want to change into hospital attire, please wear cotton clothing without any metal zippers, hooks, or buttons. The technologist will review what you are wearing and will determine if you may need to change into a gown.
Please let us know if you need interpreting services, this can be arranged for you.
Please bring a list of your current medications.
If you have claustrophobia your doctor may prescribe an oral medication for you to take with you for your MRI appointment.
The MRI machine looks like a tube that has both ends open. Our open MRI machine also has the sides open. You lie down on a movable table that slides into the opening of the tube. A technologist monitors you from another room. You can talk with the 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. Earplugs or music may be provided to help block the noise. 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.
If a dye injection is used, the IV is removed from the arm before you go home.
Allergic reaction from gadolinium dye is extremely rare. However, if you experience symptoms such as rash, hives, or shortness of breath, you should notify the technologist immediately if you are still at the imaging facility, or call your doctor or go to the nearest hospital if you have already left the imaging facility.
In the event that your doctor has prescribed you sedation, someone must drive you home.
MRI images are stored as electronic data files and usually reviewed on a computer screen. A radiologist interprets these images and sends a report to your doctor within a 48 hour period.
If you are scared about your MRI, keep in mind that people talk about MRI and claustrophobia (fear of being in a closed space) based on what they have heard or experienced in the past. Not all of this is true today, and certainly not at MRI Imaging Center of Fresno, Inc. Older MRI machines had narrower tunnels than the modern MRI equipment. The older machines were often relatively dark, and the scanner’s ceiling was very close to the patient’s face and head.
MRI Imaging Center of Fresno, Inc. has taken the following measures to help those who expect to feel claustrophobic during MRI: