Functional neuroimaging of inner fields-of-view with 2D-selective RF excitations
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Functional neuroimaging of inner fields-of-view with 2D-selective RF excitations. / Finsterbusch, Jürgen.
in: MAGN RESON IMAGING, Jahrgang 31, Nr. 7, 01.09.2013, S. 1228-35.Publikationen: SCORING: Beitrag in Fachzeitschrift/Zeitung › SCORING: Zeitschriftenaufsatz › Forschung › Begutachtung
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TY - JOUR
T1 - Functional neuroimaging of inner fields-of-view with 2D-selective RF excitations
AU - Finsterbusch, Jürgen
N1 - Copyright © 2013 Elsevier Inc. All rights reserved.
PY - 2013/9/1
Y1 - 2013/9/1
N2 - Echo-planar imaging is widely used in functional neuroimaging but suffers from its pronounced sensitivity to field inhomogeneities that cause geometric distortions and image blurring which both limit the effective in-plane resolution achievable. In this work, it is shown how inner-field-of-view techniques based on 2D-selective RF excitations (2DRF) can be applied to reduce the field-of-view in the phase-encoding direction without aliasing and increase the in-plane resolution accordingly. Free-induction-decay (FID) EPI and echo-train-shifted (T2*-weighted) and standard (T2-weighted) spin-echo (SE) EPI with in-plane resolutions of up to 0.5×1.0mm(2) (slice thickness 5mm) were acquired at 3T. Unwanted signal contributions of 2DRF side excitations were shifted out of the object (FID-EPI) or of the refocusing plane by tilting the excitation plane (SE-EPI). Brain activation in healthy volunteers was investigated with checkerboard and finger-tapping block-design paradigms. Brain activation could be detected with all sequences and contrasts, most reliably with FID-EPI due to its higher signal amplitude and the longer 2DRF excitation that are more sensitive to magnetic field inhomogeneities. In conclusion, inner-FOV EPI based on 2DRF excitations could help to improve the spatial resolution of fMRI of focal target regions, e.g., for applications in the spinal cord.
AB - Echo-planar imaging is widely used in functional neuroimaging but suffers from its pronounced sensitivity to field inhomogeneities that cause geometric distortions and image blurring which both limit the effective in-plane resolution achievable. In this work, it is shown how inner-field-of-view techniques based on 2D-selective RF excitations (2DRF) can be applied to reduce the field-of-view in the phase-encoding direction without aliasing and increase the in-plane resolution accordingly. Free-induction-decay (FID) EPI and echo-train-shifted (T2*-weighted) and standard (T2-weighted) spin-echo (SE) EPI with in-plane resolutions of up to 0.5×1.0mm(2) (slice thickness 5mm) were acquired at 3T. Unwanted signal contributions of 2DRF side excitations were shifted out of the object (FID-EPI) or of the refocusing plane by tilting the excitation plane (SE-EPI). Brain activation in healthy volunteers was investigated with checkerboard and finger-tapping block-design paradigms. Brain activation could be detected with all sequences and contrasts, most reliably with FID-EPI due to its higher signal amplitude and the longer 2DRF excitation that are more sensitive to magnetic field inhomogeneities. In conclusion, inner-FOV EPI based on 2DRF excitations could help to improve the spatial resolution of fMRI of focal target regions, e.g., for applications in the spinal cord.
KW - Algorithms
KW - Brain
KW - Brain Mapping
KW - Echo-Planar Imaging
KW - Functional Neuroimaging
KW - Humans
KW - Image Processing, Computer-Assisted
KW - Magnetic Resonance Imaging
KW - Phantoms, Imaging
KW - Software
U2 - 10.1016/j.mri.2013.03.005
DO - 10.1016/j.mri.2013.03.005
M3 - SCORING: Journal article
C2 - 23602726
VL - 31
SP - 1228
EP - 1235
JO - MAGN RESON IMAGING
JF - MAGN RESON IMAGING
SN - 0730-725X
IS - 7
ER -