TY - JOUR
T1 - Proton spectroscopic imaging of human brain
AU - Moonen, Chrit T.W.
AU - Sobering, Geoffrey
AU - Van Zijl, Peter C.M.
AU - Gillen, Joe
AU - Von Kienlin, Markus
AU - Bizzi, Alberto
PY - 1992/7
Y1 - 1992/7
N2 - Signals from water and fat can cause artifacts in proton spectroscopic imaging in the human brain. The major problem is variation of the B0 field over a range of several ppm within the sensitive volume of the standard whole-head coil. Here, the coherence-pathway formalism is used to describe and evaluate the origin of artifacts in a double spin-echo (PRESS) sequence. The attenuation of unwanted coherences using pulsed field gradients is described for homogeneous and inhomogeneous B0 fields. The effect of the following parameters on the quality of the spectroscopic images is analyzed: (a) directional order of plane selection, (b) positioning of phase-encode gradients in the sequence, (c) postprocessing spatial windowing, and (d) motion. It is shown that, for a typical echo time of 272 ms, it is not necessary to first select a region of interest within the brain borders when sufficient phase-encode steps are used. Examples of 2D proton spectroscopic images with a nominal voxel volume of 0.85 ml are given for a healthy volunteer and a patient with a low-grade glioma.
AB - Signals from water and fat can cause artifacts in proton spectroscopic imaging in the human brain. The major problem is variation of the B0 field over a range of several ppm within the sensitive volume of the standard whole-head coil. Here, the coherence-pathway formalism is used to describe and evaluate the origin of artifacts in a double spin-echo (PRESS) sequence. The attenuation of unwanted coherences using pulsed field gradients is described for homogeneous and inhomogeneous B0 fields. The effect of the following parameters on the quality of the spectroscopic images is analyzed: (a) directional order of plane selection, (b) positioning of phase-encode gradients in the sequence, (c) postprocessing spatial windowing, and (d) motion. It is shown that, for a typical echo time of 272 ms, it is not necessary to first select a region of interest within the brain borders when sufficient phase-encode steps are used. Examples of 2D proton spectroscopic images with a nominal voxel volume of 0.85 ml are given for a healthy volunteer and a patient with a low-grade glioma.
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U2 - 10.1016/0022-2364(92)90007-T
DO - 10.1016/0022-2364(92)90007-T
M3 - Article
AN - SCOPUS:44049121282
SN - 0022-2364
VL - 98
SP - 556
EP - 575
JO - Journal of Magnetic Resonance (1969)
JF - Journal of Magnetic Resonance (1969)
IS - 3
ER -