Magnetic Resonance Imaging (MRI)

.. A noninvasive technique that produces computerized images of internal body tissues based on nuclear magnetic resonance of atoms within the body induced by radio waves.

Magnetic Resonance Imaging (MRI) uses magnetism and radio waves to produce an image of the inside of the body. This technique is particularly useful for imaging the spinal cord, areas of the head where soft and hard tissue meet, and areas affected by stroke that cannot be seen well on CT scans. MRI often is used in the diagnosis of nerve fiber disorders, such as multiple sclerosis, because of its high-resolution representation of the brain’s white and gray matter.

MRI is based on magnetic properties in the interior (nucleus) of all atoms, including those in living tissue. When radio waves are directed to a specific part of the body, they cause the nuclei of atoms located there to give off energy. This energy is detected, and a computer converts the emerging pattern of magnetic energy into an image that can be interpreted by scientists. MRI has over the years given birth to other MRI-based imaging techniques, including magnetic resonance spectroscopic imaging (MRSI), and functional magnetic resonance imaging (fMRI). All work on the same basis, are non-invasive, and are used to support and enhance neuroscience research conducted at The University of Texas Health Science Center at Houston. At UT-Houston, MRI is used extensively by scientists conducting basic laboratory research as well as human research in clinical settings. UT-Houston has recently acquired a state-of-the-art high field MR scanner dedicated for animal studies. This scanner, which is only one of its kind in the whole southwest United States, is equipped with high power gradient and radio frequency coils for high resolution magnetic resonance studies of living animals. The largest animals that can be scanned are rabbits and small monkeys. The system is also equipped with mini-imaging modules that can be used to image rats and mice with very high resolution. This feature is particularly important in light of the tremendous interest in studying genetically manipulated mice.

Following are other examples of current UT-Houston studies using MRI:

Scientists are working to develop and implement newer MRI techniques to study various neurological disorders. These newer techniques can be used to follow demyelination, or destruction of the insulating sheath (myelin) that covers nerve fibers. In addition, they can be used to monitor nerve function and dysfunction in the spinal cord, as well as lesions in the brain caused by multiple sclerosis.
Newer MRI techniques will be invaluable in helping researchers to understand what happens in the body when central nervous system injuries occur, and in evaluating the efficiency of newer treatments. For example, using newer techniques developed at UT-Houston, researchers have demonstrated that nerve inflammation need not precede demyelination in multiple sclerosis, a finding that is contrary to traditional beliefs but is supported by newer MRI evidence.
The image analysis techniques developed at UT-Houston are used in a number of multi-center clinical trials of various drugs used in the treatment of multiple sclerosis patients.
Functional MRI techniques (fMRI) are used to probe causes of short-term memory losses in the prefrontal cortex of patients with schizophrenia.
Probing the areas of the brain responsible for impulsive and aggressive behavior is another way UT-Houston researchers use fMRI.
Effects of various drugs, such as alcohol, on brain function are also being studied with fMRI.
UT-Houston researchers are using MRI and MRSI to identify the areas in the brain that can lead to epileptic seizures.
To locate abnormal regions of brain activity prior to neurosurgery, researchers are developing ways to correlate information generated by various imaging techniques.

Magnetic resonance imaging, because it is noninvasive, allows repeated studies to follow progressive changes in an individual over an extended period and allows scientists to follow delayed changes brought on by trauma. MRI also provides a clear record of central nervous system damage, allowing investigators to see whether or not a particular drug or treatment caused a change.