Development of Techniques for Use in MRI With a Magnetic Field of 7 Tesla

This study will develop new techniques for optimizing resolution in magnetic resonance imaging (MRI) with a high magnetic field of 7 Tesla. MRI is a diagnostic tool that generates high-quality images of the body without the use of x-rays. It can also provide information about brain chemistry and physiology. The test is routinely done at magnetic field strengths of from 1.5 to 4 Tesla. This study will use an investigational device that operates at a high magnetic field of 7 Tesla. Except for the increase in magnetic field, all other aspects of imaging are the same as those at lower magnetic fields. This study will use techniques in conjunction with the higher magnetic field that may improve diagnostic imaging. The MRI will monitor the brain at high resolution to see structural features, to measure brain chemicals, and to determine how much and how fast blood flows into brain regions in response to simple tasks.

Healthy normal volunteers 18 years of age and older may participate in this study. Candidates will be screened with a medical history, neurological examination, and questionnaire.

Participants will have a standard 1.5 or 3 Tesla MRI before the 7 Tesla scan, adding about 5 minutes to the procedure. The procedure for both scans is the same. The subject lies on a table that is moved into the scanner. Because the machine makes loud sounds during the imaging, earplugs are provided to help reduce the noise. An insulated wire coil may be placed around the subject's head to obtain better images. Scanning time varies from 20 minutes to 3 hours, with most examinations lasting between 45 and 90 minutes. During the scan, the subject may be asked to perform simple tasks, such as listening to tones, tapping fingers, moving a hand, watching a movie on a screen, or smelling pleasant odors. More complex tasks may require thinking about tones or pictures and responding to them by pressing buttons. Following the test, subjects will complete a brief questionnaire about comfort level and any unusual sensations they may have experienced during the test.

Participants who undergo repeated MRIs for the evaluation of new techniques will have a standard 1.5 or 3 Tesla MRI brain study once a year while participating in the research protocol. A radiologist at NIH will read the MRIs, and if any abnormalities are discovered, the individual will be referred to his or her private physician or to a consult service at NIH.

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