MRI, MRA, MRCP
Magnetic Resonance Imaging (MRI), Magnetic Resonance Angiography (MRA), Magnetic Resonance Cholangiopancreatography (MRCP)
What is MRI?
Magnetic Resonance Imaging (MRI) is another way of producing precise images of the body's internal organs without the use of x-rays. The machine generates high-resolution images which appear as cross sections of anatomy. MRI uses a large magnet, radio frequencies, and a computer to produce its images. The computer processes these signals to produce highly detailed images of your anatomy. MRI is also capable of producing those images in an infinite number of projections throughout the body. These images are useful in the early discovery and treatment of many conditions and diseases.
What is MRA?
Magnetic Resonance Angiography (MRA) is a non-invasive technique on the MRI scanner to image blood vessels of any body part, most commonly those in the head and neck. MRA is an alternative to conventional angiography which requires the insertion of needles and catheters into the blood vessels with the use of x-ray.
What is MRCP?
Magnetic Resonance Cholangiopancreatography (MRCP) is a non-invasive, faster alternative to ERCP (Endoscopic Retrograde Cholangiopancreatography) in evaluating patients with yellow jaundice and suspected blockage of the liver ducts (biliary obstruction), often due to gallstones or tumors.
What is an MRI like?
You will lie on a padded scanner bed and the part of your body to be scanned will be properly positioned within the machine. Based on the type of MRI you are having and the number of images required, scans will last 20-45 minutes.
Who performs an MRI?
A certified MRI technician will assist you in preparing for the exam and placing you on the scanner bed. The exam will be conducted based on the instructions from a board certified radiologist who sub-specializes in magnetic resonance imaging.
Is MRI safe?
Because MRI uses no x-rays, it presents no apparent risk to adults and children. If you are pregnant or nursing, you should consult your physician before having an MRI scan.
How do I prepare for an MRI?
Wear comfortable clothing without metal zippers, buttons, hooks, etc.
If you are having a "with contrast" exam you are instructed to refrain from eating or drinking 2 hours before your exam.
Can anyone have an MRI?
There are some conditions that are not conducive to high-field MRI. Some of these conditions may include:
- History of a heart pacemaker
- History of metal in your body
- History of artificial heart valve
- History of brain aneurysm surgery
- Severe claustrophobia
What is the difference between an MRI and a CT scan?
MRI does not use x-rays like a CT (computed tomography) scan. With a CT, x-rays are sent through the body, one section at a time. The computer can then construct the information and create images of the body. MRI involves sending safe levels of electromagnetic waves, such as those used in radio transmission, in a safe magnetic environment. The body then sends tiny radio waves back to a computer recorder. The different cells in the body can then, in turn, create their own signal with each molecule having its own radio frequency. The computer can tell even the minute differences between the lengths of the radio waves and, using that information, can create an image of the body, one section at a time.
Because each uses an entirely different technique for imaging the body, the results display different characteristics of the body's anatomy and the diseases that affect them.