Key Points

• Chest MRI is a safe, noninvasive test. It creates detailed pictures of the structures in your chest, like your chest wall, heart, and blood vessels. Radio waves, magnets, and a computer are used to make these pictures.
• Chest MRI is used to look for tumors in the chest; look at blood vessels, lymph nodes, and other structures in the chest; and help explain results from other tests, such as chest x ray and chest CT scan.
• You may need a chest MRI if your doctor suspects you have a chest condition, such as a tumor, a problem in the blood vessels (such as an aneurysm or blood clot), abnormal lymph nodes, or other chest conditions.
• Before a chest MRI, your doctor or the MRI technician will ask you questions about your health to make sure an MRI is safe for you. You should not wear or bring metal or electronic objects into the MRI room. The MRI can damage these items, and they can interfere with the MRI machine.
• An MRI machine looks like a long, narrow tunnel. New machines are shorter and wider and don’t completely surround you; others are open on all sides. Tell your doctor if you’re afraid of tight or closed spaces. He or she may give you medicine to help you relax or find you a place that has an open MRI machine.
• Before the test, your doctor may inject a special substance (called contrast dye) into a vein in your arm. This dye allows the MRI to take more detailed pictures of the structures in your chest.
• If you’re breast-feeding, ask your doctor how long you should wait after the test before you breast-feed. The contrast dye can be passed through your breast milk. You may want to prepare for the test by pumping and saving milk for 24 to 48 hours in advance. You can bottle-feed your baby in the hours after the MRI.
• A chest MRI is painless. During the test, you lie on your back on a sliding table as it passes through the MRI machine. The machine takes pictures of your chest. Moving your body can cause the pictures to blur. You will be asked to remain very still during the test.
• You usually can return to your normal routine right after a chest MRI. If you got medicine to help you relax, your doctor will tell you when you can return to your normal routine. The medicine may make you tired, so you’ll need someone to drive you home.
• Chest MRI has few risks. Rarely, the contrast dye used for some chest MRIs may cause an allergic reaction.