What is MRI?
Magnetic resonance imaging, or MRI, uses a strong magnet and radio waves to provide clear and detailed diagnostic images of internal body organs and tissues. MRI is a valuable tool for the diagnosis of a broad range of conditions, including:
- heart and vascular disease
- joint and musculoskeletal disorders
MRI allows evaluation of some body structures that may not be as visible with other diagnostic imaging methods. MRI can also image in all planes and angles with superior tissue contrast.
What are some common uses of MRI?
Imaging of the Musculoskeletal System:An MRI is often used to study the knee, ankle, foot, shoulder, elbow, wrist, and hand. MRI is also a highly accurate method for evaluation of soft tissue structures such as tendons and ligaments, which are seen in great detail. Even subtle injuries are easily detected. In addition, MRI is used for the diagnosis of spinal problems including disc herniation, spinal stenosis, and spinal tumors.
Imaging of the Vascular System: An MRI of the heart, aorta, coronary arteries and blood vessels is a tool for diagnosing coronary artery disease and other heart problems.
Imaging for Cancer & Functional Disorders:Organs of the chest and abdomen such as the liver, lungs, kidney, and other abdominal organs can be examined in great detail with MRI. This aids in the diagnosis and evaluation of tumors and functional disorders. Furthermore, because there is no radiation exposure involved, MRI is often used for examination of the male and female reproductive systems.
How should I prepare for an MRI?
- Before your MRI exam, remove all accessories including hairpins, jewelry, eyeglasses, hearing aids, wigs, dentures. During the exam, these metal objects may interfere with the magnetic field, affecting the quality of the MRI images taken.
- Notify your technologist if you have:
- any prosthetic joints – hip, knee
- a heart pacemaker (or artificial heart valve) or defibrillator
- an intrauterine device (IUD)
- any metal plates, pins, screws, or surgical staples in your body
- tattoos and permanent make-up.
- a bullet or shrapnel in your body, or if you’ve ever worked with metal
- if you might be pregnant or suspect you may be pregnant
- if you are claustrophobic. Some patients who undergo MRI in an enclosed unit may feel confined. If you are not easily reassured, a sedative may be administered.
What should I expect during this exam?
Depending on how many images are needed, the exam generally takes 15 to 45 minutes. However, very detailed studies may take longer.
- You must lie down on a sliding table and be comfortably positioned.
- Even though the technologist must leave the room, you will be able to communicate with them at any time using an intercom.
- If necessary, we allow a friend or family member to stay in the room with you during the exam. Please be aware that the friend/family member will be required to go through a written clearance to be in the exam room.
- You will be asked to remain still during the actual imaging process. However, between sequences, which last between 2-15 minutes, slight movement is allowed.
- Depending on the part of the body being examined, a contrast material may be used to enhance the visibility of certain tissues or blood vessels. A small needle is placed in your arm or hand vein and a saline solution IV drip will run through the intravenous line to prevent clotting. About two-thirds of the way through the exam, the contrast material is injected.
What will I experience during an MRI?
- MRI is painless.
- Some claustrophobic patients may experience a “closed in” feeling. If this is a concern, a sedative may be administered. Also, newer open MRI machines have helped to alleviate this reaction.
- For certain scans you have the opportunity to go in “feet first” with a portion of your body outside of the modality.
- You will hear loud tapping or thumping during the exam. Earplugs or earphones will be provided.
- You may feel warmth in the area being examined. This is normal.
- Throughout the exam you will feel a cool air flow.
- If a contrast injection is needed, there may be some discomfort at the injection site. You may also feel a cool sensation at the site during the injection.
- MRI: Medline Plus: MedlinePlus is the National Institutes of Health’s Web site for consumers. Produced by the National Library of Medicine, it brings you reliable, up-to-date health information.
- RadiologyInfo.org: Current and accurate patient information about diagnostic radiology procedures, interventional radiology and radiation therapy.