Currently, the vast majority of magnetic resonance imaging and functional imaging studies are conducted at relatively low magnetic fields of 1.5 or 3.0 Tesla. However, theoretical considerations as well as experimental evidence have suggested that there is a fundamental dependence of image signal to noise ratios, functional imaging contrast and spatial specificity on the magnetic field strength. More recently, it has been suggested that even routine anatomic imaging has potential advantages at high magnetic fields. Thus far, in humans, functional imaging studies have only been done at fields as high as 7 Tesla. Much of the experimental data suggesting advantages for higher field studies have been acquired using animal models. While animal studies provide us with data that can elucidate the biophysics of MRI/fMRI in certain cases, they are not necessarily fully applicable to the human brain. Furthermore, almost all of the studies in humans or animals at high magnetic fields have been done using limited field of views and / or a single or few slices. Shorter T2*s, increased susceptibility effects, increased physiological noise, increased SAR, and inhomogeneous B1 fields can all hinder the advantages offered by high magnetic fields. To alleviate some of the problems associated with these issues and thereby making high field imaging more attractive for general applications of the whole brain, technical development is required. With the recent growth and development of parallel imaging and parallel imaging techniques, including transmit and receive coil arrays, many of these problems commonly observed at high magnetic fields can be addressed. In addition, sequence modification and new sequence design can also help to significantly reduce the technical problems associated with high field studies. The general aim of this proposal is development of fMRI and MRI techniques for whole brain acquisitions at high magnetic fields (7 T & 9.4 T). In achieving this aim, fMRI/MRI studies will be conducted at the ultra-high magnetic field of 9.4 Tesla for the first time in humans. Furthermore, we will systematically compare the advantages of higher field systems with lower field systems (3 T) for general applications. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
2R01EB000331-05
Application #
7211752
Study Section
Biomedical Imaging Technology Study Section (BMIT)
Program Officer
Mclaughlin, Alan Charles
Project Start
2002-07-01
Project End
2011-06-30
Budget Start
2007-09-01
Budget End
2008-06-30
Support Year
5
Fiscal Year
2007
Total Cost
$331,475
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Goerke, Ute (2016) Spatial specificity in spatiotemporal encoding and Fourier imaging. Magn Reson Imaging 34:562-73
De Martino, Federico; Zimmermann, Jan; Muckli, Lars et al. (2013) Cortical depth dependent functional responses in humans at 7T: improved specificity with 3D GRASE. PLoS One 8:e60514
U?urbil, Kâmil (2012) Development of functional imaging in the human brain (fMRI); the University of Minnesota experience. Neuroimage 62:613-9
Smith, Stephen M; Miller, Karla L; Moeller, Steen et al. (2012) Temporally-independent functional modes of spontaneous brain activity. Proc Natl Acad Sci U S A 109:3131-6
Feinberg, David A; Yacoub, Essa (2012) The rapid development of high speed, resolution and precision in fMRI. Neuroimage 62:720-5
Olman, Cheryl A; Harel, Noam; Feinberg, David A et al. (2012) Layer-specific fMRI reflects different neuronal computations at different depths in human V1. PLoS One 7:e32536
U?urbil, Kâmil (2012) The road to functional imaging and ultrahigh fields. Neuroimage 62:726-35
Hu, Xiaoping; Yacoub, Essa (2012) The story of the initial dip in fMRI. Neuroimage 62:1103-8
De Martino, Federico; Schmitter, Sebastian; Moerel, Michelle et al. (2012) Spin echo functional MRI in bilateral auditory cortices at 7 T: an application of B? shimming. Neuroimage 63:1313-20
Schmitter, Sebastian; Bock, Michael; Johst, Sören et al. (2012) Contrast enhancement in TOF cerebral angiography at 7 T using saturation and MT pulses under SAR constraints: impact of VERSE and sparse pulses. Magn Reson Med 68:188-97

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