MRI is used for a variety of diagnostic purposes. It is most often used to obtain information that hasn't been provided by other imaging techniques, including ultrasound, conventional x-ray, or computed tomography.
In general, MRI is used to:
- Determine exactly what the problem is inside the body
- Show exactly where the problem is
- Rule out certain diseases
Because MRI produces images in any plane, it is particularly valuable in studying the brain and spinal cord and pinpointing even the smallest abnormality there. Because the water and fat content of tumors is different from surrounding normal tissue, MRI can reveal the precise location and size of tumors.
- Provides images of the internal structure of the eye and ear
- Produces detailed images of the heart and major blood vessels
- Provides images of blood flow in the circulatory system
- Produces detailed images of joints and soft tissues, particularly of cartilage, ligaments and tendons within joints such as the knee
Some additional diseases and medical conditions identified by MRI include:
- Disorders of chest and lungs
- Disorders of abdominal organs and the digestive tract
- Disorders of the kidneys, urinary tract and pelvic organs
- Inflammatory conditions
- Trauma and other injury
MRI in the Diagnosis of
One of the most recent and valuable uses for the MRI is in the diagnosis of strokes.
A new kind of MRI machine can pinpoint spots of dying tissue deep within the brain during the first hours of a stroke, when a blood clot in the head is choking off the oxygen supply.
This new technology comes in two varieties:
Both these technologies work by measuring how easily water flows through the brain.
Both of these MRI procedures take just a few minutes and cost about the same as "ordinary" MRI scans, although the machines capable of taking these enhanced images are more expensive.
Nice To Know:
"Real Time" Stress MRI - Pictures of the Heart in Motion
Fast cine magnetic resonance imaging is a new type of "stress" test that offers an alternative for diagnosing coronary (heart) artery disease. For those patients whose poor health precludes the standard stress tests, such as stress echocardiography, treadmill exercise tests, or thallium stress tests, fast cine MRI can prove invaluable for finding problems with the heart in such patients.
Fast cine MRI utilizes a new technology that allows imaging of the heart in "real time," This means that the imaging process is synchronized with the heart's cycle so that images are taken over numerous heartbeats in a 5- to 10-minute interval. Fast cine MRI captures the heart's movement at almost the same time that the heart is contracting and relaxing-close to "real time."
The MRI stress tests takes approximately 35 minutes, and most patients tolerate the procedure well. The test has proved to be an accurate predictor of heart disease. Among those who had a negative MRI stress tests, 97 percent were free of heart disease during the first year following testing.
The test has advantages for those who aren't suited for the standard stress tests, such as:
The test should not be used in people who have: