Commonly asked Questions about the MRI Exam

What is MRI?
Magnetic resonance imaging (MRI) is an imaging technique used primarily in medical settings to produce high quality images of the inside of the human body.

Why MRI?
A benefit of MR is that, unlike conventional x-ray or CT imaging, it does not use x-ray radiation. Magnetic resonance imaging is non-invasive and provides exquisite images with excellent contrast detail of soft tissue and anatomic structures like gray and white matter in the brain or small metastatic lesions (cancers) in the liver. In comparison to MR, conventional x-ray provides images of dense structures like bones with good resolution. Prior to MR Angiography, the invasive x-ray angiogram was the traditional method for imaging vessels like the carotid arteries in the neck, vessels in the brain, peripheral arm and leg vessels, or the coronary arteries, which supply blood to the heart. But conventional x-ray angiographic imaging is very labor and time intensive, expensive, and

requires administration of significant amounts of contrast to image the blood vessels. X-ray angiography does not provide good images of the soft tissue organs in the body like the liver or brain. Like MR, Computed Tomography (CT) also creates detailed cross sectional images of the body. But while CT can depict soft tissue structures much better than conventional x-ray, it does not have the contrast detail that MR provides. Many diseases are more readily apparent in MR images than in the corresponding CT images due to the better contrast definition of MR. MR imaging is unique in that it can also create detailed images of blood vessels without the use of contrast media (although there is a trend toward the use of special MR-contrast media called Gadolinium when imaging the vessels as well as soft tissue like the brain).

How do I get my exam's results?
Results from your MRI exam may be obtained from your doctor. Your referring physicians will contact you with the results or discuss them with you at your scheduled follow-up appointment.

Can I listen to music during the exam?
Yes!

Will the MR imaging examination hurt?
No, MR imaging itself should cause no pain. MR imaging requires that the patient remain still during the examination. For some patients, keeping still for the 15 -20 minute exam may be slightly uncomfortable. MR imaging examinations which require the patient to receive Gadolinium contrast may cause slight, temporary discomfort at the time of injection. (see below section "Do I need an injection").

How long will the MR examination take?
Depending on the type of exam you receive, the length of the actual procedure will typically be between 15 minutes and 20 minutes per procedure. Some MR exams require the patient to hold their breath several times, helping to eliminate motion artifacts from the images.

Why does the MR system make the knocking sound during the exam?
The tapping or knocking noise heard during the MR exam is created when "gradient coils" are switched on and off. Depending on the type of study being performed, earplugs or headphones may be used to dampen the sound. Please discuss this with the technologist before your examination. During the MR examination, the technologist and patient may communicate at any time via intercom or a "squeeze ball" call button. The gradient coil is one of several internal parts of the MR system that you cannot see. The gradient coil is made up of loops of wire which are embedded in a hard plastic tube. During the scanning process an electric current is switched on and off through the gradient coil approximately every few milliseconds. Because the switching is so rapid, the wires vibrate within the hard plastic and cause the knocking sound. This knocking is not harmful, but the sound can be distracting to some patients. You will hear different knocking sounds during the MR exam; this means that different types of "MR sequences" are being run to acquire different views and images of your body.

Why may I need to have an x-ray image before my MR imaging exam?
MR imaging involves the use of a strong magnetic field. This magnetic field pulls on many metal objects. Thus, for safety reasons, our staff must determine if you unknowingly have metal in your body. Some patients may have small pieces of metal in their eyes, a metal implant, a prosthetic device that may contain metal, surgical clips or other implanted objects that may be susceptible to the magnetic field. After asking you a few questions, x-ray imaging may be necessary to screen for metallic items prior to the MR examination.

Will the MR imaging affect the fillings in my teeth?
If the fillings in your teeth are in proper condition, MR imaging will not dislodge them. The metal in most fillings is not affected by the MR system's magnetic field. However, the fillings may cause some distortion of the images if you are having a scan of your neck, brain or facial area.

Can I have an MR exam if I have braces on my teeth?
Patients with braces may receive an MR imaging examination. However, if you have braces and need MR imaging of your brain or facial area, the MR system may have difficulty "tuning" to your body. The MR tuning process is similar to tuning a radio to a specific frequency or radio station. This tuning process can be "confused" if the patient has metal in his or her body, particularly if the metal is in the area being imaged. Unfortunately, there is no way to know in advance how much distortion from braces may result on MR images of the head, face or upper neck.

Do I have to go all the way inside the MR scanner?
Only the portion of the body that is being imaged must be positioned in the middle (end to end and side to side) of the MR system. For example, if a head study is being performed, the patient's head must be positioned in the middle of the scanner. For knee studies, the knee is positioned in the middle of the scanner with the patient's head facing the open end or possibly outside of the open end of the scanner (depending on the height of the patient).

Do I need a referral (prescription) to receive an MR examination?
No. But to have your examination covered by your insurance plan, your doctor must give you a referral (prescription). Self-referrals are becoming more and more popular with low-cost, non-contrasted MRI screening studies such as Cardiac MRI, Non-Invasive Prostrate Exams, screening for Alzheimers, and examinations for breast implant leakage.

Can I move while I am in the MR scanner?
You should not move when you are inside the scanner and hear the knocking sound. For most MR exams, you may reposition your arms or scratch your face or body between image acquisition, when the knocking has stopped and are instructed by the technologist. However, it is important that you not move the body part being imaged until the entire exam is complete. Some MR exams of the chest and abdomen may require the patient to hold their breath for a short period of time, for example, 10 to 20 seconds. This eliminates blurring in the image caused by motion artifacts.

Can I talk with anyone during the scan?
You may talk to the technologists or ask a question between image acquisition sequences when the knocking has stopped. The technologist will inform you when a picture is complete. At the end of a sequence, you will also notice that the knocking and slight vibration will stop.

Do I need an injection of contrast for my MRI exam?
Not everyone needs an injection for MR imaging. When an injection is needed, a pharmaceutical contrast agent called Gadolinium is administered to the patient. This is only done when the radiologist and/or the referring physician has determined that it is necessary for diagnostic purposes. Gadolinium contrast is used to make specific organs, blood vessels or tissue types "stand out" with more image contrast in the resulting picture, yet, unlike most contrast agents, it is not a dye. The contrast agent highlights the structure of the specific organs or vessel to better show the presence of disease or injury. The referring doctor provides our office with a prescription and information about the patient's medical condition and the goal of the MR imaging procedure being ordered (for example, to diagnose cause of intense back pain). The decision to use or not to use an injection of contrast (Gadolinium) is made based on this information and the body part being examined.

How is the Gadolinium injection given for an MR imaging exam?
If an MR exam does require the use of a Gadolinium injection, a small needle, connected to an intravenous line, is usually inserted into the patient's arm or hand. A special saline solution is first dripped in to keep the vein from clotting. Then typically, about two-thirds through the exam, a contrast agent will be administered through the intravenous line. At the time of the injection, a patient may feel a cool sensation in his or her arm.

Can I breast feed after an injection of Gadolinium?
Typically, patients are instructed to wait for 24 hours after receiving the Gadolinium injection before breast-feeding again. Patients may wish to pump breast milk prior to the MR exam and store it for use during this 24-hour period. Always check with your physician for their specific recommendations.

Can I have an MR imaging exam if I am pregnant?
This question is difficult to answer with a simple "yes" or "no." MRI is considered a safe exam, however, conclusive information showing how safe MRI is for pregnant women and the fetus is not yet available. Although there are no medical contraindications, MR imaging is generally not performed on women in the first twelve weeks of pregnancy (first trimester). Physicians typically do not perform MRI on pregnant women unless there are strong medical indications. Depending on the condition, there may be other exams available, such as ultrasound, to help diagnose a medical condition. If there is a strong medical reason for an MRI, your physician may consult with a radiologist to determine if MRI is the best course of action before proceeding. An abbreviated MRI exam may be performed, to reduce the time in the magnetic field, based on the recommendation of the referring physician and radiologist. Please consult with your physician for more specific information.