Magnetic Resonance Imaging is a non-invasive scanning modality that uses magnetic fields and radio frequencies to produce images of the inside of the human body.

The MRI scanners used by UMI are superconductive magnets shaped somewhat like a donut, only longer—visualize several stacked on end—with a hole or tunnel all the way through.

MRI is a unique imaging method because, unlike the more common radiographs (X-rays) and CT scanning, it does not rely on radiation. Instead, radio waves are directed at protons, the nuclei of hydrogen atoms, in a strong magnetic field. The protons are first “excited” and then “relaxed,” and emit radio signals which can be processed by a computer to form an image. In the body, protons are most abundant in the hydrogen atoms of water—the “H” of H2O—so that an MRI image shows differences in the water content and distribution in various body tissues. Even different types of tissue within the same organ, such as the gray and white matter of the brain, can easily be distinguished.

MRI causes no pain. Most bothersome to many patients are the loud tapping or knocking noises heard at certain points during the imaging process. You may also feel a slight vibration when the knocking occurs. Hearing protection will be provided: earplugs result in the most protection, but headphones and radio may be made available for certain procedures. You may also experience some warmth at the area of imaging but should not experience heat or burning.

When you undergo an MR exam, you will be placed on a sliding table and a radio antenna device called a surface coil is positioned around the body part being examined. After positioning your body so the area of interest is inside the MRI gantry, the technologist leaves the room and the individual MRI sequences are performed. The inside of the scanner is lighted, and gentle fans constantly circulate fresh air through the opening during an exam. You will be able to communicate with the technologist at any time using an intercom. You will be asked not to move during the actual imaging process. At your request, you can be given a call bell to notify the technologist while the scanner is imaging. The exam may be stopped at any time.

Some patients require an injection of a contrast material to enhance the visibility of certain tissues or blood vessels. Under those circumstances, a small needle connected to an intravenous line will be placed in a vein in your arm or hand. (If needed, this will be performed about two-thirds of the way through the exam.) As the contrast material is injected, you may experience a cool sensation at the injection site.

When the exam is finished, you will be asked to wait until the images are examined to determine if more images are needed.

Typically an MRI exam consists of six or more imaging sequences, each lasting 2 to 15 minutes. Depending on how many images are needed, the entire exam will generally take 30 minutes, although an exam covering a larger area or more body parts will take longer.

General preparation tips 

• Please bring a photo ID. Federal "RED FLAG" regulations require that we verify your identity at each visit.
• Please bring all relevant insurance information; your referral paperwork; and copies of X-rays and/or any prior exams.
• Please arrive 30 minutes prior to the scheduled exam time to complete a medical screening form. It is important to fill out all information on the form (surgeries, medications, etc.) and let UMI staff determine its relevance with regard to your specific exam conditions.
• You will be escorted to a dressing room to change into a gown for your procedure. You will be asked to remove all jewelry and any clothing with a metallic component. Although lockers are provided, we ask that you leave your valuables at home.
• Your entire stay for the exam is estimated at 1 to 2 hours, including advance arrival time. Certain multiple exam procedures may take longer.

Metal objects and/or implants

As its name implies, Magnetic Resonance Imaging uses magnetic fields to generate its images. Metallic objects can significantly disrupt MRI imaging or even cause harm to you or the staff. Therefore, no metal (with the exception of some internal implants) may be on your person during the exam. With this in mind, please be advised of the following:

• Please notify the UMI technologist of any artificial implants or foreign objects. To determine MRI safety:
  • X-ray pictures may be taken to confirm presence or absence of metallic implants.
  • Contacting the surgeon and implant manufacturer may be required.
• Head and neck MRIs require the removal of dentures or partials.
• For your convenience, please leave any jewelry and hairpins at home. They must be removed for the exam.

Claustrophobia 

• If you are known to experience claustrophobia and would like sedation for your exam, please consult your referring physician to see if he or she will write you a prescription in advance of your UMI visit. Please be advised that UMI does not provide this medication.
• Patients undergoing MR of the head will have a mirror to see out of the scanner. For other MR procedures, you may request the use of prism glasses that allow you to see outside the scanner during the procedure. We can even provide you with a special blindfold that you can take home with you after your procedure. Fresh air is also constantly circulated throughout the lighted scanner.

Special conditions 

Please contact us in advance of your appointment if any of the following conditions pertain to you:

• If you have had spinal surgery in the past and are scheduled for an early morning, evening or weekend spinal exam.
• Please be advised that your breathing may not be assisted with an oxygen tank during an MRI exam.
• If you have artificial implants (pacemaker, aneurysm clips, etc.), please notify UMI the day prior to your appointment and bring your implant card with you to the exam.
• UMI is unable to accommodate patients confined to stretchers. If this applies to you, your exam must be conducted at Strong Memorial Hospital.
• If you use a wheelchair, be advised that UMI has limited appointments to normal weekday business hours only (i.e., no evenings or weekends). UMI does not have a Hoyer lift so we are unable to perform full transfers from wheelchair to exam table. Wheelchair patients must be capable of assisting with the transfer.
• The table used in the MRI exam has a weight limit of 350 lbs. If your weight exceeds this figure, please contact us in advance so that alternative imaging procedures or locations may be discussed.

Contrast injection 

• Certain MRI scans require an injection of an odorless and colorless contrast known as gadolinium. This injection is given in a vein near the elbow, generally with a butterfly (very small) needle or IV catheter.
• Side effects to this contrast are extremely rare, with the most common being a mild sensation of nausea (which passes after several minutes) and hives that might appear approximately 20 minutes after the injection. However, if you have severe asthma, are allergic to multiple medications or have previously had an allergic reaction to MRI contrast, please contact our nursing department at 341-9230 prior to your appointment.
• Please be aware that gadolinium is iodine-free. UMI routinely checks the results of recent blood tests as a precaution for those patients who are renal compromised. If you are on dialysis, please contact our nursing department at 341-9230 prior to your appointment.
• The contrast will not impair your ability to drive, and will pass harmlessly in your urine within 24 hours after the completion of the exam.

For more detailed information on many radiology procedures, please visit this informationalsite.

As always, you can visit www.universitymedicalimaging.com, or call our main office at (585) 341-9100 with questions.