Development of Techniques for Use in MRI With a Magnetic Field of 7 Tesla
| Status: | Completed |
|---|---|
| Conditions: | Healthy Studies |
| Therapuetic Areas: | Other |
| Healthy: | No |
| Age Range: | 18 - Any |
| Updated: | 4/21/2016 |
| Start Date: | March 2003 |
| End Date: | January 2010 |
Development of 7 Tesla MRI Methodology for Anatomical Functional and Spectroscopic Imaging of the Brain
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.
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.
The goal of this protocol is to optimize new technology that enables Magnetic Resonance
Imaging (MRI) at a static magnetic field strength of 7 Tesla (7T). Techniques will be
developed for anatomical, functional, and spectroscopic MRI that can take advantage of this
high field. Routine clinical MRI has been performed at 1.5T for over twenty years and over
the past ten years MRI at 3-4T has demonstrated large increases in sensitivity and is
beginning to find widespread application for functional imaging of the brain and clinical
research. Since the late 1990's it has been possible to produce magnets with field strengths
between 7-9T large enough for human use. Indeed there are presently two sites with 7T and
one with 8T MRI that have begun to produce exciting images. These initial results confirm
that MRI can be performed safely at these high field strengths and that the whole range of
MRI experiments can be performed. We will take delivery of the first 7T MRI system produced
by General Electric, the leading producer of MRI equipment, sometime in late 2002/early
2003.
Compared to 3-4T, the 7T scanner is expected to improve sensitivity by a factor of two and
improve contrast to noise for functional imaging and spectroscopy by a factor of two - four.
However, realizing these goals for routine practice and whole brain coverage will require
technical developments and integrating these developments into optimized data acquisition
and processing strategies. Therefore, we plan to extend parallel imaging strategies,
currently becoming available for 3T MRI, to 7T in order to realize the full gain in
sensitivity and apply these techniques to obtain high resolution anatomical MRI, generate
high temporal and spatial resolution perfusion images using arterial spin labeling
techniques, generate high-temporal and spatial resolution functional images of the brain
using blood oxygenation (BOLD) and perfusion based techniques, and test the usefulness of 7T
for spectroscopic studies of metabolites of the brain. All of these developments will be
performed on normal, healthy volunteers.
Imaging (MRI) at a static magnetic field strength of 7 Tesla (7T). Techniques will be
developed for anatomical, functional, and spectroscopic MRI that can take advantage of this
high field. Routine clinical MRI has been performed at 1.5T for over twenty years and over
the past ten years MRI at 3-4T has demonstrated large increases in sensitivity and is
beginning to find widespread application for functional imaging of the brain and clinical
research. Since the late 1990's it has been possible to produce magnets with field strengths
between 7-9T large enough for human use. Indeed there are presently two sites with 7T and
one with 8T MRI that have begun to produce exciting images. These initial results confirm
that MRI can be performed safely at these high field strengths and that the whole range of
MRI experiments can be performed. We will take delivery of the first 7T MRI system produced
by General Electric, the leading producer of MRI equipment, sometime in late 2002/early
2003.
Compared to 3-4T, the 7T scanner is expected to improve sensitivity by a factor of two and
improve contrast to noise for functional imaging and spectroscopy by a factor of two - four.
However, realizing these goals for routine practice and whole brain coverage will require
technical developments and integrating these developments into optimized data acquisition
and processing strategies. Therefore, we plan to extend parallel imaging strategies,
currently becoming available for 3T MRI, to 7T in order to realize the full gain in
sensitivity and apply these techniques to obtain high resolution anatomical MRI, generate
high temporal and spatial resolution perfusion images using arterial spin labeling
techniques, generate high-temporal and spatial resolution functional images of the brain
using blood oxygenation (BOLD) and perfusion based techniques, and test the usefulness of 7T
for spectroscopic studies of metabolites of the brain. All of these developments will be
performed on normal, healthy volunteers.
- INCLUSION CRITERIA:
Only neurologically and psychiatrically normal, male or female, healthy volunteers over 18
years old will be used in these studies. Subjects must be capable of understanding the
procedures and requirements of this study. Subjects must be willing to sign an informed
consent document.
EXCLUSION CRITERIA:
A subject will be excluded if he/she has a contraindication to MR scanning such as the
following: pregnancy, aneurysm clip; implanted neural stimulator; implanted cardiac
pacemaker or auto-defibrillator; cochlear implant; ocular foreign body (e.g. metal
shavings or insulin pump), dental work such as crowns or bridges with indeterminate
metals, pre-existing eye conditions, and any pre-existing hearing problems. Subjects who
underwent brain surgery, who have a neurological lesion, a psychiatric history or a
history of migraine will also be excluded from this study. The contraindications for MRI
at 7T are identical to those at 1.5T and 3T.
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Bethesda, Maryland 20892
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