MRI/ Magnetic Resonance Imaging
MRI is short for Magnetic Resonance Imaging. MRI does not use ionizing radiation, as CT scans and x-rays do. Instead, MRI generates images using a very strong magnet and radio waves. The images are cross sections like CT scans, but MRI can also produce images in lengthwise planes without the patient having to change position. The unique sensitivity of MRI to changes in soft tissue, as well as its very high resolution, allows for the visualization of changes that may not be seen in other imaging exams. MRI excels at imaging soft tissues such as the breasts, internal organs, muscles, cartilage and the brain and spinal cord. It is also very sensitive to subtle changes in bones. Not everyone may be a candidate for MRI. Due to the strong magnet used, some implanted materials and devices are not safe to image. Before you undergo MRI, you will be asked to complete a questionnaire to ensure that it is safe for you to undergo MRI. Conventional MRI machines have a donut shape with a tube that is usually about 4-5 feet in length. This exam causes anxiety for some people who are claustrophobic. If you know you are claustrophobic, please let our staff know at the time of scheduling.
What does the equipment look like?
Table and MRI Gantry
Reasons for having an MRI
MRI is used for imaging many parts of the body. MRI can be used to evaluate the cause of headaches, back pain, shoulder, knee and other joint injuries. MRI is also frequently used to image the abdominal and pelvic organs. MRI may be used as a tool to make an initial diagnosis, or it can be used to follow an existing illness or injury.
MRA (Magnetic Resonance Angiography) scans require the use of a contrast medium, also referred to as gadolinium. Gadolinium, which is given intravenously, highlights certain body parts so the can better see any abnormalities.
Women who have been diagnosed breast cancer or who have a suspicious lump or mass may undergo a breast MRI and/or needle guided biopsy to gather additional information. A breast MRI can help a physician determine the most appropriate type of surgery for breast cancer. Breast MRIs are also often recommended for women with a strong family history of breast cancer, a genetic risk, scar tissue from previous breast surgery, implants, or dense breast tissue. Since these factors may cause a mammogram to show incomplete information, a breast MRI may be used in addition to the more traditional imaging, including mammography and ultrasound.
How do I prepare for a MRI scan?
Please leave your jewelry and valuables at home. Any jewelry that is difficult to remove should be taken off at home prior to the exam. Do not wear eye makeup. Female patients must notify their physician if they are or think they might be pregnant, for further instructions. Unless you are told otherwise, you may follow your regular daily routine and take medications as usual. MRI with sedation: Nothing but clear liquids 4 hours before the exam. Nothing by mouth for 2 hours before the exam (except small amount of water if needed to take medication). Arrange for someone to drive you to and from the exam.
What will I experience during and after the procedure?
The MRI technologist will explain the procedure, ask you some safety questions, and answer any questions you might have. Before your exam begins, you will be asked to remove all metal and metallic objects, such as eyeglasses, belt, hair accessories and jewelry. You may also be asked to change into a gown. You will lie on a table for the exam. It is extremely important not to move any part of your body during the MRI scan to avoid blurring the images. A device called a coil will be placed on or around the area being imaged. Padding may be used to prevent inadvertent movement.
Breast MRI scans and biopsies are performed with you lying on your stomach with your breasts hanging freely through an opening in the table. If you are unable to lie on your stomach for any reason, notify us well in advance of your appointment. Both breasts will be imaged unless your physician specifically requests that only one breast be imaged. You will be awake during your biopsy and should have little or no discomfort. Generally the biopsy is completed in less than an hour. Most patients are able to resume their usual activities later the same day. Beast MRI exams last about 45 minutes.
If your MRI was ordered with contrast medium (gadolinium), several series of scans will be taken before the injection is given, then a few more will be taken after the injection. For the injection, you will have a small IV placed in your hand prior to entering the exam room. The IV will remain in place until the exam is completed.
During scanning, the MRI machine produces loud buzzing and knocking sounds. You will be provided with earplugs to protect your hearing. The technologist will not stay in the room during the scan, but you can speak with him or her throughout the exam by intercom.
Most MRI exams last only 20-30 minutes. Some specialized exams may take longer.
You can return to your normal activities immediately after your MRI unless you received a sedative. If you were sedated, you must refrain from driving after the exam.
Who interprets the results and how do I get them?
A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will share the results with you. In some cases the radiologist may discuss preliminary results with you at the conclusion of your examination.