Magnetic Resonance Imaging of the Chest
Magnetic resonance imaging (MRI) uses a strong magnetic field combined with radiofrequency waves to create highly detailed, cross-sectional images of internal structures; these scans are examined for abnormalities. MRI of the chest is particularly valuable for providing detailed images of blood vessels and soft tissues in the chest cavity, such as the lung anatomy, their surrounding membrane, or pleura, and the lymph nodes.
Purpose of the Chest MRI
- To evaluate abnormal masses in the chest, including lung cancer that cannot be properly assessed with other imaging modalities (typically chest CT scan) or that are particularly well-suited to MRI
- To detect and evaluate abnormalities, such as tumors or other growths, in chest organs and tissues
- To detect and evaluate blood vessels problems in the chest cavity, such as an aneurysm (abnormal outpouching) or stenosis (narrowing) of the aorta; blood vessel malformations in the lungs; and certain abnormalities of the cardiac blood vessels
- To evaluate heart anatomy, function and structures, such as heart valves
- To evaluate blood flow to the heart (myocardial perfusion)and scarring of the heart muscle due to previous blood flow obstruction (infarct)
- To assess blood flow within the vessels and heart chambers
- To assess lymph nodes and blood vessels and detect vascular and lymphatic malformations of the chest
- To evaluate disorders of the chest bones (vertebrae, ribs and sternum) and soft tissues of the chest wall (muscles and fat)
- To evaluate the pericardium (thin sac around the heart)
- To evaluate structures of the chest from multiple planes
- To detect a tear in the aorta, the body's largest artery
- To help diagnose disorders of the airways and chest wall
- To clarify findings from previous x-rays or CT scans of the chest
Who Performs Chest MRI
- A radiologist or a qualified technician
Special Concerns about Chest MRI
- People with claustrophobia may find it difficult to undergo this procedure, which takes place in a narrow, tunnel-like structure. In some cases, an open MRI—a larger unit that is open on several sides—may be used as an alternative.
- This test may not be possible for severely overweight individuals (over 300 lbs). Some open MRI scanners can accommodate larger patients.
- Because the MRI generates a strong magnetic field, it cannot be performed on people who have certain types of internally placed metallic devices, including pacemakers, inner ear implants, or intracranial aneurysm clips.
- The test is not commonly done in pregnant women because the long-term effects of MRI on the fetus are unknown.
Before the Chest MRI
- Do not to eat or drink for 4 - 6 hours before chest MRI.
- Tell your doctor if you suffer from claustrophobia (fear of enclosed spaces) or anxiety. He or she may prescribe a sedative that can help you tolerate the procedure.
- Tell your doctor if you have any allergies, including an allergy to iodine or x-ray contrast material.
- Tell your doctor if you have any serious health concerns or if you had recent surgery.
- Tell your doctor if you are pregnant or may be pregnant.
- For your comfort, you will be instructed to empty your bladder before the test.
- Remove any magnetic cards or metallic objects, including watches, hair clips, belts, credit cards, hearing aids, metal zippers, removable dental work, pens, pocketknives, eyeglasses, body piercing and jewelry.
- You may be asked to disrobe and put on a hospital gown.
What You Experience during Chest MRI
- You will lie down on a narrow padded bed that slides into a large, enclosed cylinder containing the MRI magnets.
- You must remain still throughout the scanning procedure because any motion can distort the images.
- There is a microphone inside the imaging machine, and you may talk to the technician performing the scan at any time during the procedure.
- You will hear loud thumping sounds as the scanning is performed. To block out the noise, you can request earplugs or listen to music on earphones.
- The entire procedure may require up to 90 minutes.
- No discomfort is associated with this test.
Risks and Complications of Chest MRI Scan
- MRI does not involve exposure to ionizing radiation. The test is not associated with any risks or complications.
- Contrast material may cause side effects such as headache and nausea. Serious reactions are very rare.
After the Chest MRI
- Most patients can go home promptly after the scan is completed and resume their usual activities.
- Sedated patients may be monitored for a short period until the effects of the sedative have worn off.
Results of Chest MRI
- The MRI scans are displayed on a viewing monitor and then recorded on film. The doctor will examine them for evidence of any abnormality.
- If a definitive diagnosis can be made based on these images, your doctor will recommend an appropriate course of treatment, depending on the specific problem.
- In some cases, additional tests, such as a chest CT scan or bronchoscopy, may be required to establish a diagnosis or determine the extent of a problem.
The Johns Hopkins Consumer Guide to Medical Tests
Simeon Margolis, M.D., Ph.D., Medical Editor
Updated by Remedy Health Media