You may be able to have an MRI with an open MRI machine that doesn't enclose your entire body. But open MRI machines aren't available everywhere. The pictures from an open MRI may not be as good as those from a standard MRI machine.
Sometimes your MRI results may be different from earlier test
results because you were tested at a different medical center or you had a
different kind of test.
Several special MRI methods have been
developed to look at the brain.
Magnetic resonance spectroscopy
shows changes in brain chemistry that may occur in certain areas of the brain.
These changes may help show diseases that affect the brain.
Magnetic resonance angiography (MRA) can be used to study
blood vessels. Dye may be injected into the blood vessels so blood flow can be
seen clearly. MRA can also be used to show the speed and direction of blood
flow. To learn more, see the topic
Magnetic Resonance Angiogram (MRA).
Diffusion-perfusion imaging shows the water content and
character of the brain. This method can give an early diagnosis of a
stroke and may help predict the outcome of stroke. It
can also be used to find tumors or inflammation of the brain.
Functional MRI (fMRI) measures small chemical changes in the brain, which can show the part of the brain being used for functions such as speech, thought, or movement of body parts. Results from fMRI can be used to locate areas of the brain to avoid during brain surgery. These results can also be used to see how well the brain is functioning in people who have certain conditions.