An MRI, or magnetic resonance imaging, provides a view of the soft tissue of the body through the use of a super magnet and radiofrequency signals, reports RadiologyInfo.org. Images transmitted to a computer screen are then interpreted by a radiologist and discussed with the patient’s physician. Physicians use MRIs as a diagnostic tool in the case of a suspected disease, stroke, brain injuries or cancer.
Disease
Diseases such as multiple sclerosis or Alzheimer’s show up on an MRI as loss of brain tissue or plaque deposits, respectively. After the initial MRI, MRIs are repeated throughout the process of the disease to show its progression. Abnormal MRIs may also indicate hydrocephalus, an excess amount of spinal fluid on the brain. Osteomyelitis--an infection of the bone, or skull, in the brain--and brain abscesses also appear on abnormal MRIs.
Brain Injury
A stroke originated by a blood clot in the brain may cause brain tissue death. The extent of the damage will appear on the MRI. Old strokes that may not have been apparent to the patient will also appear. Brain tissue swelling resulting from a blow to the head will appear as an expansion of the brain to the limits of the skull as cerebrospinal fluid is displaced. Aneurysms—the bulging of a blood vessel—and other malformations in blood vessels can be diagnosed or monitored for change with an MRI.
Cancer
Pituitary tumors and brain cancer will result in an abnormal MRI. Two cranial nerves--the second and eighth--produce abnormal MRI readings, according to the National Institutes of Health. Optic glioma, a cancer of the optic, or second, cranial nerve which is responsible for vision, and acoustic neuroma, a tumor of the eighth cranial, or vestibulococchlear, nerve which is responsible for hearing and equilibrium can also result in an abnormal MRI.
Active Brain Bleed
Blunt trauma to the brain such as a deep bleed in the case of a subdural hematoma can also be diagnosed, and the exact location pinpointed, by an MRI. Other bleeding, such as that from a hemorrhagic stroke, can also be found with the use of an MRI.
Abnormal Brain Structures
Abnormalities of brain structures such as the brain ventricles, pituitary gland, lobes and brain hemispheres produce abnormal MRIs.
References
- National Institutes of Heatlh: MRI, What Abnormal Results Mean
- RadiologyInfo.org: MRI of the Head
- "Taber's Cyclopedic Medical Dictionary"; F.A. Davis; 2009
- "A Manual of Laboratory and Diagnostic Tests;" Frances Talaska Fischback, R.N., B.S.N., M.S.N.; 2004
