(MRI Scan of the Breast)
Magnetic resonance imaging (MRI) is a diagnostic procedure that uses a combination of a large magnet, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
The MRI machine is a large, cylindrical (tube-shaped) machine that creates a strong magnetic field around the patient. The magnetic field, along with a radiofrequency, alters the hydrogen atoms' natural alignment in the body. Computers are then used to form a two-dimensional (2D) image of a body structure or organ based on the activity of the hydrogen atoms. Cross-sectional views can be obtained to reveal further details. MRI does not use radiation, as do X-rays or computed tomography (CT scans).
A magnetic field is created and pulses of radio waves are sent from a scanner. The radio waves knock the nuclei of the atoms in your body out of their normal position. As the nuclei realign into proper position, they send out radio signals. These signals are received by a computer that analyzes and converts them into an image of the part of the body being examined. This image appears on a viewing monitor. Some MRI machines look like narrow tunnels, while others are more open.
For a breast MRI, the woman usually lies face down, with her breasts positioned through openings in the table. In order to check breast positioning, the technologist watches the MRI through a window while monitoring for any potential movement.
A breast MRI usually requires the use of a contrast dye that is injected into a vein in the arm before or during the procedure. The dye may help create clearer images that outline abnormalities more easily.
MRI, used with mammography and breast ultrasound, can be a useful diagnostic tool. Recent research has found that MRI can locate some small breast lesions sometimes missed by mammography. It can also help detect breast cancer in women with breast implants and in younger women who tend to have dense breast tissue. Mammography may not be as effective in these cases. Since MRIs do not use radiation, they may be used to screen women younger than 40 and to increase the number of screenings per year for women at high risk for breast cancer.
Although it has distinct advantages over mammography, breast MRI also has potential limitations. For example, it is not always able to distinguish the difference between cancerous abnormalities, which may lead to unnecessary breast biopsies. This is often referred to as a "false positive" test result.
Recent research has demonstrated that using commercially available software programs to enhance breast MRI scans can reduce the number of false positive results with malignant tumors. Thus, the need for biopsies may decrease with computer-aided enhancement.
Another disadvantage of breast MRI is that it has historically been unable to identify calcifications or tiny calcium deposits that can indicate breast cancer.
The most recent guidelines from the American Cancer Society include screening MRI with mammography for certain high-risk women. This option should be considered for the following:
Some common uses for breast MRI include:
There may be other reasons for your doctor to recommend breast MRI.
Because radiation is not used, there is no risk of exposure to radiation during an MRI procedure.
Due to the use of the strong magnet, MRI cannot be performed on patients with implanted pacemakers, older intracranial aneurysm clips, cochlear implants in the ear, certain prosthetic devices, implanted drug infusion pumps, neurostimulators, bone-growth stimulators, certain intrauterine contraceptive devices, or any other type of iron-based metal implants. MRI is also contraindicated in the presence of internal metallic objects such as bullets or shrapnel, as well as surgical clips, pins, plates, screws, metal sutures, or wire mesh.
If you are pregnant or suspect that you may be pregnant, you should notify your health care provider. Due to the potential for a harmful increase in the temperature of the amniotic fluid, MRI is not advised for pregnant patients.
MRI is generally not advised for patients with epilepsy.
If contrast dye is used, there is a risk for allergic reaction to the dye. Patients who are allergic to or sensitive to medications, contrast dye, or iodine should notify the radiologist or technologist.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Your doctor will explain the procedure to you and offer the opportunity to ask any questions that you might have about the procedure.
If your procedure involves the use of contrast dye, you will be asked to sign a consent form that gives permission to do the procedure. Read the form carefully and ask questions if something is not clear.
Personal items, such as your watch, wallet, including any credit cards with a magnetic strip (which may be erased by the magnet), will be left in a locker or other secure place prior to the MRI scan.
Before the examination, it is extremely important that you inform the technologist if any of the following apply to you:
As there is a possibility that you may receive a sedative before the procedure, you should plan to have someone drive you home afterwards.
Based on your medical condition, your doctor may require other specific preparation.
MRI may be performed on an outpatient basis or as part of your stay in the hospital. Procedures may vary depending on your condition and your doctor's practices.
Generally, a breast MRI follows this process:
While the MRI procedure itself causes no pain, having to lie still for the length of the procedure might cause some discomfort or pain, particularly in the case of a recent injury or invasive procedure such as surgery. The technologist will use all possible comfort measures and complete the procedure as quickly as possible to minimize any discomfort or pain.
You should move slowly when getting up from the scanner table to avoid any dizziness or lightheadedness from lying prone for the length of the procedure.
If any sedatives were taken for the procedure, you may be required to rest until the sedatives have worn off. You will also need to avoid driving.
If contrast dye was used during your procedure, you may be monitored for a period of time for any side effects or reactions to the contrast dye, such as itching, swelling, rash, or difficulty breathing.
If you notice any pain, redness, and/or swelling at the IV site after you return home following your procedure, you should notify your doctor, as this could indicate an infection or other type of reaction.
It is recommended that nursing mothers not breastfeed for 36 to 48 hours after a breast MRI with contrast dye.
Generally, there is no special type of care required after a MRI scan of the breasts. You may resume your usual diet and activities, unless your doctor advises you differently.
A radiologist will analyze the images and provide a report to your doctor.
Your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.
The content provided here is for informational purposes only, and was not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your doctor. Please consult your doctor with any questions or concerns you may have regarding your condition.
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