Magnetic Resonance Imaging
MRI, or Magnetic Resonance Imaging, is a state-of-the-art technique that allows doctors to see inside the human body in remarkable detail without using x-rays. MRI images are produced with the use of a powerful magnetic field, radio waves and a sophisticated computer system. The procedure is safe and painless.
Both MRI and CT scans make cross-sectional images (slices) of pretty much any area of the body using a sophisticated computer system. The major difference is that an MRI uses a large magnet and radio waves to produce images, while a CT scanner uses x-rays. Therefore, with the MRI studies, there is no exposure to x-rays. Both systems complement each other well as they both have their inherent strengths and weaknesses; however, CT usually can only directly acquire transverse (or crosswise) images, whereas MRI can directly acquire slices in any plane. In addition, MRI is superior when it comes to soft tissue contrast, and there are no known side effects. The ability to view pictures from multiple directions, high tissue contrast and lack of x-rays make MRI a very powerful and increasingly popular imaging tool. Please note, MRI is very sensitive to motion during the acquisition of pictures and, in some instances, CT is preferable is the patient is unable to stay still.
MRI utilizes the physical properties of magnetic fields, radio waves and computers to generate images of the tissues within the body. MRI signals from the body are generated using a safe magnetic field in combination with radio waves of a specific frequency. The MRI signals are detected and converted to a form which the computer can understand. The computer processes the MRI signals from the body to form the MR images. Different tissue characteristics are revealed through this process and are thereby translated into different contrast levels in the MR images. The trained doctor can then view the MR images and form a clinical diagnosis.
The MRI procedure will typically last anywhere from 30 to 60 minutes, depending on the type of information required by the doctor. To conduct the MR study, a technologist will assist the patient onto a padded, moveable scanning table. The table and patient are positioned inside the opening of the MR scanner. The patient is easily observed by the technologist throughout the study, and is able to speak with technologist or doctor at any time. The patient is only required to remain as still as possible during the unusual. A variety of sounds, such as humming and thumping noises, will be heard as the scan progresses. This is normal, and a sign that the exam is proceeding as required. After the exam, the patient may resume all normal activities.
In the days before the MRI scan, a patient may follow all normal routines, such as eating and taking regular medication. Immediately prior to the MR scan, the technologist or doctor will provide an explanation of the MR process. The patient is asked to remove any metal objects, such as jewelry or non-permanent dentures. Any metal object might be attracted to the MR scanner’s magnet, and thereby hinder the procedure. Bank cards and credit cards are also restricted from the scan room, as the magnetic field could erase information contained on the. As a final precaution, the patient will be asked a series of questions to insure that there are no metal or electrical objects inside the patient.
Upon arrival, you will be greeted and registered by our receptionist, and any papers and/or diagnostic studies will be collected at this time. Next, you will be shown to a secure change room and asked to remove any metallic objects, such as jewelry, glasses, hairpins, hearing aids and possibly non-permanent dentures. Wallets, credit cards and purses must also be left behind in our secure change rooms. Prior to the start of the scan, our technologist will conduct a brief interview with you regarding your medical history and the possible presence of metallic objects in your body. Finally, you will be taken into the scanning room where the technologist will have you lie on the padded examination table.
The average exam takes 45 minutes on the high field, one hour on the open field. It may take more or less than this depending on what part of the body is being studied.
In order to get the best picture possible, the part of the body being studied has to be in the middle of the scanner. Thus, if you are having a brain MRI, your head will have to be in the middle of the scanner. If you are having an ankle MRI, your ankle will be in the scanner, but your head will not. If you have severe claustrophobia, ask your doctor for some medication to help you relax during the scan. Please have someone accompany you who can drive you home if you do take any medication.
Yes. An MRI exam is composed of a series of images. Each series takes 3 to 5 minutes. Any movement during this time causes the pictures to be “blurry” and limits the radiologist’s ability to interpret the study. Also, we focus the exam on a specific part of the body. If you move, the area we are focusing on may no longer be in the proper position.
Most people who have metal in their body after surgery can have an MRI. For example, patients with hip or knee replacements can have an MRI 6 weeks after surgery. Other implanted devices require less time after surgery. Certain devices can never go into the MRI machine. Heart pacemakers, and some implanted pumps and nerve stimulators cannot go in the MRI scanner. If you have had any prior surgery, you must let the technologist know prior to the scan. Also, if there is any chance there may be metal in any part of your body from a prior injury or from grinding metal, please inform the technologist prior to the scan.
We normally do not scan pregnant women. If you think you might be pregnant, you must have a pregnancy test done or wait until your menstrual period before we can scan you. If you are breast-feeding, an unenhanced routine MRI is no problem. However, if there is the possibility of your scan being unenhanced with the contrast media, you should plan on bottle-feeding the baby for 48 hours after the scan until the contrast material has passed out of your system.
Our Radiologist will interpret your scan, it will get transcribed, signed, and your doctor should receive a written report in 2 to 3 business days. If requested by your doctor, a report can be called to him/her the day of the exam. You can get the results from your doctor. Please do not ask the technologist or staff for your results. Only your doctor or his/her staff can give your results to you.
Yes. The results will only be shared with your referring doctor and no one else without your permission.