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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1994-8-5
|
| pubmed:abstractText |
Suppression of the water signal during 1H magnetic resonance spectroscopy by repeated sequences of a frequency-selective radiofrequency pulse and a gradient dephasing pulse requires nulling of the longitudinal component of the water magnetization and is therefore affected by T1 relaxation, RF-pulse flip angles (which depend on B1), and sequence timing. In in vivo applications, T1 and B1 inhomogeneity within the sample may cause spatially inhomogeneous water suppression. An improved water-suppression technique called WET (water suppression enhanced through T1 effects), developed from a Bloch equation analysis of the longitudinal magnetization over the T1 and B1 ranges of interest, achieves T1- and B1-insensitive suppression with four RF pulses, each having a numerically optimized flip angle. Once flip angles have been optimized for a given sequence, time-consuming flip-angle adjustments during clinical examinations are eliminated. This water-suppression technique was characterized with respect to T1 variations, B1 variations, off-resonance effects, and partial saturation effects and was compared to similar techniques. Effective water suppression has been achieved with this new technique in single-voxel spectroscopy examinations of more than 50 brain tumor patients at 1.5 T.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
May
|
| pubmed:issn |
1064-1866
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
104
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
1-10
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading | |
| pubmed:year |
1994
|
| pubmed:articleTitle |
WET, a T1- and B1-insensitive water-suppression method for in vivo localized 1H NMR spectroscopy.
|
| pubmed:affiliation |
Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, Tennessee 38101.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|