What Information Is Found in an MRI of the Brain?

Magnetic resonance imaging, or MRI, is a noninvasive medical test that uses a powerful magnetic field, radio frequency pulses and a computer to produce a detailed picture of the body, displaying parts of the body such as organs, soft tissues, bone and other internal body structures. Patients undergoing the procedure swallow a contrast material to aid in the clear production of the images, and lie still in the MRI machine while it scans. MRI can be used to help diagnose several medical conditions in the brain.

Tumors

• A brain tumor is an abnormal mass of cells growing in the brain. Tumors can be primary, which means they begin by growing in the brain, or secondary, which means the tumor spread from a cancer originating in another part of the body. While an MRI can show the tumor, only a biopsy can determine if the tumor is benign or malignant.

Strokes

• Strokes occur when the blood supply to part of the brain stops, resulting in the loss of brain cells. An MRI scan can be used to identify where in the brain the stroke occurred and the extent of the damage.

Trauma

• A traumatic brain injury is a head injury in which the impact results in brain damage. While the area of the brain where the injury occurred can be determined by the symptoms displayed by the patient, an MRI can show exactly where the lesion is and how badly damaged the brain is. Lesions generated from a traumatic brain injury can also resemble lesions from a stroke.

Chronic Disorders of the Nervous System

• Chronic disorders of the nervous system, like multiple sclerosis, can show up in an MRI scan. Multiple sclerosis is a disease where there is demyelination of the brain. Demyelination is the loss of myelin, which wraps around the axon of a neuron, and can be seen through a decrease in the white matter of the brain. In other chronic disorders caused by birth anomalies, the MRI can also show the brain region that has been affected, and the extent of the damage.

Problems

• Even though an MRI can provide a good image of the brain, which is useful for diagnosing problems in the brain, there can be problems identifying the abnormality. For instance, doctors might not always be able to distinguish between cancerous tissue and fluid from edema in the brain.