MRI

Magnetic resonance imaging (MRI) is a noninvasive imaging technique. This special machine is used to view organs, bone and other internal body structures.

 

The imaged body part is exposed to radio waves while in a magnetic field. The picture is produced by energy emitted from hydrogen atoms in the human body. An individual is not exposed to radiation during this test.

 

MRI can be used for a variety of purposes. A MRI of the brain, known as a cranial MRI, may be ordered by a healthcare professional to evaluate an individual's seizure disorder, headache, or other neurological symptoms.

 

A MRI of the spine may be requested to examine the discs between a person's vertebrae. If an individual has sustained injury to the shoulder or knee, a MRI is frequently used to study these large joints. Disease of the heart, chest, abdomen and pelvis are also commonly evaluated with MRI.

 

Before the test, the healthcare professional will ask if the person:

 

A woman will also be asked if she might be pregnant. If she is, the exam is not done. As the test begins, the person lies on a flat platform. The platform then slides into a donut-shaped magnet where the scanning takes place. To prevent image distortion on the final images, the person must lie very still for the duration of the test.

 

Commonly, a special substance called a contrast agent is administered prior to or during the test. The contrast agent is used to enhance internal structures and improve image quality. Typically, this material is injected into a vein in the arm. The scanning process is painless. However, the part of the body being imaged may feel a bit warm. This sensation is harmless and normal.

 

Loud banging and knocking noises are heard by the person during some parts of the exam. Earplugs are provided for people who find the noises disturbing. After the test, the person is asked to wait until the images are viewed to see if more images are needed. If the pictures look satisfactory, the person is allowed to leave.

 

Before the test, the person will be asked to remove all metal objects such as belts, jewelry, and any pieces of removable dental work. Internal metal objects that cannot be removed may distort the final images. The person should inform the MRI technologist about any previous surgery which required placement of metal, such as a hip pinning.

A specially trained doctor called a radiologist usually analyzes and interprets the MRI images. Frequently, the MRI will help to better evaluate a disease or disorder affecting organs and blood vessels.