Eliminating side excitations in PROPELLER-based 2D-selective RF excitations.
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Eliminating side excitations in PROPELLER-based 2D-selective RF excitations. / Busch, Martin; Finsterbusch, Jürgen.
In: MAGN RESON MED, Vol. 68, No. 5, 5, 2012, p. 1383-1389.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
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TY - JOUR
T1 - Eliminating side excitations in PROPELLER-based 2D-selective RF excitations.
AU - Busch, Martin
AU - Finsterbusch, Jürgen
PY - 2012
Y1 - 2012
N2 - Recently, spatially two-dimensional selective radiofrequency excitations based on the PROPELLER trajectory have been presented and were applied to minimize partial volume effects in single-voxel MR spectroscopy. Thereby, residual side excitations appeared due to limitations of the Voronoi diagram that was used to consider the nonconstant sampling density, and trajectory distortions caused by eddy currents varying between the differently rotated blades. In this extension, one of the refocusing radiofrequency pulses of a PRESS-based pulse sequence is applied in the blip direction of each segment to eliminate the side excitations. This corresponds to an infinitely dense sampling of the blade and the required sampling density correction can easily be calculated. Thus, signal contributions from outside the desired region-of-interest are completely avoided. The feasibility of this approach to acquire single-voxel MR spectra of anatomically defined regions-of-interest is demonstrated in the human brain in vivo on a 3T whole-body MR system.
AB - Recently, spatially two-dimensional selective radiofrequency excitations based on the PROPELLER trajectory have been presented and were applied to minimize partial volume effects in single-voxel MR spectroscopy. Thereby, residual side excitations appeared due to limitations of the Voronoi diagram that was used to consider the nonconstant sampling density, and trajectory distortions caused by eddy currents varying between the differently rotated blades. In this extension, one of the refocusing radiofrequency pulses of a PRESS-based pulse sequence is applied in the blip direction of each segment to eliminate the side excitations. This corresponds to an infinitely dense sampling of the blade and the required sampling density correction can easily be calculated. Thus, signal contributions from outside the desired region-of-interest are completely avoided. The feasibility of this approach to acquire single-voxel MR spectra of anatomically defined regions-of-interest is demonstrated in the human brain in vivo on a 3T whole-body MR system.
KW - Reproducibility of Results
KW - Sensitivity and Specificity
KW - Artifacts
KW - Algorithms
KW - Magnetic Resonance Spectroscopy/methods
KW - Reproducibility of Results
KW - Sensitivity and Specificity
KW - Artifacts
KW - Algorithms
KW - Magnetic Resonance Spectroscopy/methods
M3 - SCORING: Journal article
VL - 68
SP - 1383
EP - 1389
JO - MAGN RESON MED
JF - MAGN RESON MED
SN - 0740-3194
IS - 5
M1 - 5
ER -
