Magnetic Resonance Imaging (MRI)
This noninvasive medical imaging technique uses a powerful magnetic field to create a detailed three-dimensional view of the inside of the body. The images it produces are similar to those generated by a CT scan. However, MRI images provide a much clearer view of soft tissues. This makes MRI a valuable diagnostic tool for the visualization of cancer, infection, internal bleeding and soft tissue trauma.
Before an MRI, the patient is advised to remove items such as glasses, jewelry, dentures and dental bridges. Patients with certain types of surgical implants cannot receive an MRI. Devices such as plates, screws, cardiac defibrillators, pacemakers, cochlear implants, and certain types of brain clips and implanted metal coils cannot be placed in an MRI. In most cases, pregnant women are not given MRIs.
The patient may be asked to wear a gown. The patient may also be given hearing protection. Young children and people who have extreme anxiety may be sedated to help them remain motionless and comfortable during the scan.
Administering Contrast Material
In some cases, the scan may require the use of a contrast material. This material will provide a clearer image of the area to be scanned. Patients may be given an oral contrast agent, or it may be administered intravenously.
Once the patient is in position, the machine is activated. The patient will hear a series of loud sounds, including banging and humming noises. A scan may take between 30 and 90 minutes. The patient must remain still during this time so that the image is not blurred. If the patient moves, the scan may need to be stopped and restarted from the beginning.
The scan is monitored by a technician located in an adjacent room who can view the MRI imagery as it is gathered. A microphone and speaker allow the patient and technician to communicate during the scan.
Once the MRI is complete, the images are reviewed by a radiologist and a report is sent to the referring physician. The physician will discuss the results with the patient and will discuss any treatment options.