Services
Magnetic Resonance imaging (MR)
How MR imaging works
Magnetic Resonance imaging, or MRI, produces detailed pictures by using a magnetic field, radio waves and sophisticated computer processing to provide clear and detailed diagnostic images of internal body organs and tissues. MRI is a valuable tool for the diagnosis of a broad range of conditions.
The advantages of MRI include:
- No x-rays
- No known health risks except for patients with specific conditions please click here
A device (Imaging “coil”) may be placed around the part of the body being studied. Radio waves are then directed to the portion of the body being studied and the returning radio wave signal is received by the coil and sent to a specialized computer.
The MR computer reads the radio waves and processes them into digital pictures (images). These images are analyzed by our radiologists. A report will be dictated and sent to your physician along with the images. Our MR scanners have been evaluated and accredited by the American College of Radiology
Precautions, Risks and complications
MR imaging should not be done under certain circumstances, and there are precautions that must be observed in other cases. Before your examination, you will be asked whether or not you have any of the following:
- Cardiac pacemaker
- Cerebral (brain) aneurysm clips
- Certain heart valves
- Insulin pumps or other infusion pumps
- Cochlear (inner ear) implants
- Neurostimulator (nerve stimulator)
- Metals in the body, especially in your eyes (workers such as metal workers and automotive mechanics are especially at risk for this)
- Pregnancy or certain types of intrauterine devices such as Copper-7 IUD
- A history of kidney disease or people who are on dialysis
In many cases, MR imaging is completely non-invasive, in other words, there are no injections. In some situations, an intravenous contrast agent (“dye”) is needed and is given by injection during the examination. All contrast materials used are FDA approved and considered safe. MR contrast agents are specific to MR imaging, and are different from and have fewer allergic reactions than the iodine-containing contrast used for CT scans and kidney x-rays.
There are no known health risks associated with the magnetic field or radio waves used in MR imaging.
Preparation
No advance preparation is required. Eat normally and take any medication as usual, unless your doctor has given you other instructions.
What to expect
You will be asked to remove jewelry, your watch, credit cards, dentures, hearing aids and any metal objects that could be affected by the magnetic field. You will also need to change into comfortable clothing which we provide for your examination. A locker will be available for your use as well. We encourage you to leave any unnecessary valuables at home.
In the imaging room, you will be positioned on a softly padded table that will be moved into the MR machine by the technologist. Depending on the part of your body that is being studied, a small device (coil) will be placed over, or around the part of the body being examined. It is not constricting, and acts as a receiver for the radio waves produced by the MR machine.
If only a single part of your body (i.e, head, back or knee) is being studied, the examination takes no more than 30-60 minutes. Each study is made up of a series of sequences, providing a set of images taken at different angles, emphasizing different characteristics of the tissue being studied. For example, a typical knee MRI is 5 sequences; an examination of the head for headaches is 6 or 7 sequences. With each sequence, you will hear a loud rhythmic thumping noise and may feel a slight vibration, but there should be no other physical sensations.
Throughout your study, your technologist will be able to hear and see you. Your job during the examination is simply to relax and remain still. The quality of your MR study depends very much on your ability to hold still. As in a time exposure photograph, the MR image will blur if you move.
While the space in the MR machine is adequate for most individuals, some people may feel uncomfortable. Please let us know if you have concerns with claustrophobia or being in confined spaces, before your appointment. Occasionally, a patient will need a moderate sedative to be comfortable in the MR machine. If this is the case you will need to bring someone to drive you home.