Magnetic resonance imaging (MRI) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. MRI uses a powerful magnetic field, radio frequency pulses, and a computer to produce detailed pictures of organs, soft tissues, bone, and a host of other internal body structures. The images can then be displayed and examined on a computer monitor, transmitted electronically, printed or copied to a CD.
Why am I getting an MRI rather than a CT?
Detailed MR images allow physicians to better evaluate various parts of the body and determine the presence of certain diseases that may not be assessed adequately with other imaging methods such as x-ray, ultrasound, or CAT scan. It is important to note that MRI does not use x-rays.
If there's no radiation, why would I ever get a CT scan?
Obtaining MRI images takes much more time than a CT scan. Areas in the body that move in short periods of time, like your lungs or bowel, may not be ideal for MRI. Air doesn't contain a lot of protons and is largely invisible on MRI. Remember that lungs are mostly air.
Are there any needles? Why do I need contrast?
Depending on what information your doctor needs, the MRI scan may require the use of a contrast-agent given intravenously to assist in the visualization of certain anatomical structures in your body.
I've heard that some people can't have MRI's. Can I have an MRI?
Please advise your doctors and their scheduling staff if you have any implanted devices. At the time that you schedule your exam with us, our schedulers will ask you if you have any implanted device and even more detailed questions about the make and model of these devices. The reason for these questions, which, at times may slow the phone process down, is that certain implants may prevent you, for safety reasons, from having your exam. Asking as much information up front will help us make your experience at the time of the scan as efficient and as fast as possible. Examples of problematic implants include:
- cardiac pacemakers or old pacemaker wires
- brain aneurysm clips
- middle ear prostheses
These are only a few of the implanted devices, so please tell the intake personnel and your technologist if you have any prosthetic device (i.e., hip or knee replacement, etc). As you can see, for your safety, it is important that we have many checks and balances in place before you have your scan.
Patients should not wear any eye makeup or hairspray. Believe it or not, they contain metal and can cause problems in a magnet.
What do I need to bring with me?
Please fax your prescription to scheduling at (212) 263-2290 when you schedule your appointment. This will help the Radiologist prepare for your exam before you arrive. Please bring previous imaging study results (x-ray, MRI, CT, etc.) such as reports, films or CD-ROMs if performed at another facility and they are available. On the day of your exam, you will need to bring your prescription, insurance card, and any related insurance forms or pre-approvals. We are able to play a variety of music during your MRI—if you have a preference simply bring a CD or iPod.
Preparing for an MRI
Preparation for your MRI will depend on the type of exam you are having.
Do I need to be fasting? Will I have to drink that awful stuff?
If you are having a Cholangiogram (MRCP – Magnetic Resonance Cholangiopancreatography), you will have to fast for four hours prior to your exam. If you are having an MR-enterography exam, you will be required to drink oral contrast.
Do I need to have my creatinine level performed before my exam?
If your doctor has ordered an MRI with contrast (Gadolinium) and you have a history of diabetes, kidney (renal) issues, or hypertension, you'll have to have your creatinine level obtained prior to your MRI. The blood test must be acquired within 6 weeks of your exam. The blood work must be performed within one week of the exam for all patients who have had or will be having a liver transplant.
What should I wear?
Gowns will be provided for your exam. We have private dressing rooms with lockers for your clothes and valuables, although we recommend that you leave your valuables at home.
You will be asked to remove ALL body piercings, jewelry, watches, eyeglasses, hairpins, wallets, and other metallic objects prior to your exam.
I am claustrophobic; will I be able to have a scan?
Many of our scanners have short bore technology which makes for a more comfortable scanning experience. "Short bore" means that the length of the tube you're in during your scan is shorter than usual. Unless you are having a scan of your head or neck, you may be able to see outside of the magnet. We ask that you discuss this condition with your physician. If sedation is prescribed by your doctor, bring it with you on the day of your exam. Inform the front desk staff upon arrival that you need to take prescribed medication for your exam.
When should I arrive for my appointment?
When you schedule your appointment, our scheduling associate will let you know how soon before your appointment time you should arrive. Depending on the exam, it may be 30-60 minutes before your scheduled appointment. This will allow you enough time to register and to complete all necessary paperwork, forms, or questionnaires. It may save you time to download, print, and fill out the appropriate forms at home and bring them with you on the day of your appointment.
What if I might be pregnant?
Please indicate any possibility of pregnancy to your physician and the scheduling office when you book the appointment. Inform the MRI technologist as well when you arrive at the department.
During my MRI
After you have removed all metal objects, our MRI Technologist will position you on the table of the scanner. Your head will be placed in a padded plastic cradle or on a pillow, and the table will slide into the scanner. An intercom system will allow you and the technologist to be able to communicate with one another at all times.
In order to obtain clear pictures, you will be asked to hold very still and relax. In some cases, you will be asked to hold your breath for up to 20 seconds. Any movement, especially of your head or back (even moving your jaw to talk) during the scan will blur and degrade the pictures. While the machine is taking your pictures, you will hear rapid, loud thumping noises coming from the scanner. During this time, you should breathe quietly and normally and refrain from any movement, coughing or wiggling. When the thumping noise stops, you must be still and maintain your position in the scanner. This noise comes from the gradient that allows the magnet to produce images.
There will be multiple series of image acquisition, each with its own particular noises. The entire exam ordinarily takes between 30 and 60 minutes depending on exam type.
After your MRI
After your procedure, you will be escorted back to the dressing room. In most cases you will be able to leave at this point and resume regular diet and activities. There are occasional procedures which will require that you stay and be monitored afterward. If you brought prior studies for comparison, these will be waiting for you at the front desk.
How will I know the results of my MRI?
After your MRI our subspecialized radiologists will read the images and dictate a report that will be sent immediately to your referring physician, who will contact you with the results.