An MRI (Magnetic Resonance Imaging) scan is a painless radiology imaging technique that utilizes a large circular magnet and radio waves which are fed into a computer to produce images. One advantage of an MRI is that it avoids radiation exposure to the patient. The image resolution of an MRI scan is very detailed. Contrast material can also be injected to a patient to enhance the accuracy of certain types of images.
The MRI machine itself is a rather large and expensive piece of equipment that is usually shaped like a tube. The patient is placed on a small gurney like tray that moves into the tube where the images are obtained. During the scan, the patient may hear clicking noises as the scanning process occurs. Most MRI scans last between a half hour to an hour and a half depending on the area being studied. Modern technology has advanced to allow the design of MRI machines that are open (not a closed tube) so that large patients can fit better and/or to help alleviate patient anxieties of claustrophobia. More recent technology has developed a Stand-UP MRI machine that allows images to be taken while the patient is in a seated position. MRI's in the flexion and extension positions offer the most accurate diagnosis of herniated spinal discs.
MRI's can be used to scan parts of the entire body. Common MRI scans include those of the neck and spine, brain, extremities, or other areas which have been traumatically injured. An MRI can detect aneurysms, strokes, tumors, disc herniations and evaluate many other soft tissues of the body.
Although there are no known side effects of receiving an MRI scan, patients who have any metallic materials embedded within their bodies should tell their physicians before undergoing an MRI scan. Because the MRI utilizes a large magnet which attracts metal objects, a physician must provide clearance to any patient who has any metal inside their body.Patients with pacemakers or metal chips or clips in their eyeballs cannot be scanned with an MRI machine.
Another potential issue relating to the use of the MRI involves monitoring. Some patients who are critically ill and who require constant monitoring of the vital signs must undergo MRI scans. Since the MRI machine utilizes a large magnet, these patients cannot enter the scanner with the ordinary monitoring devices attached to their bodies. In this circumstance, the ordering physician must either use special monitors designed for use in the MRI machine OR have a nurse or technician stand next to the patient and manually monitor them.
More than one medical malpractice case has arisen when a patient arrests during an MRI scan and suffers irreversible brain damage because no one knew the patient was arresting since no monitoring devices were attached.