Abstract:
:Two NMR experiments are described that use ac field gradients to measure flow velocities. Both experiments perform no spacial localization; instead, fluid velocity is converted to a resonance frequency shift. Thus, by Fourier transformation of a single FID or echo train the distribution of velocities is available. The first experiment uses only one rf pulse but requires a homogeneous static field. The second experiment uses the CPMG multiple-pulse sequence to refocus the effects of field inhomogeneity and chemical shifts. Results are shown for both experiments using a simple flowing phantom. Applications of the techniques to time-resolved blood flow measurement are discussed.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
Walton JH,Conradi MSdoi
10.1002/mrm.1910040308subject
Has Abstractpub_date
1987-03-01 00:00:00pages
274-81issue
3eissn
0740-3194issn
1522-2594journal_volume
4pub_type
杂志文章abstract::Hyperpolarized 129Xe has been used to obtain gas phase images of mouse lung in vivo, showing distinct ventilation variation as a function of the breathing cycle. Spectra of 129Xe in the thorax show complex structure in both the gas phase (-4 to 3 ppm) and tissue-dissolved (190-205 ppm) regions. The alveolar gas peak s...
journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.21925
更新日期:2009-04-01 00:00:00
abstract::A receive-only phased-array coil was designed to image the lower extremities. The array consists of four volume coils placed on two cylindrical formers. The coil array has the ability to image both legs simultaneously over a 40 cm longitudinal field of view (FOV). Experiments using phantoms show an increase in signal-...
journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10712
更新日期:2004-03-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22428
更新日期:2010-08-01 00:00:00
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journal_title:Magnetic resonance in medicine
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doi:10.1002/mrm.1074
更新日期:2001-04-01 00:00:00
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doi:10.1002/mrm.20175
更新日期:2004-09-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.1910320406
更新日期:1994-10-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.22544
更新日期:2010-11-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
doi:10.1002/mrm.10626
更新日期:2003-11-01 00:00:00
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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更新日期:1998-02-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2004-12-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:2010-07-01 00:00:00
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journal_title:Magnetic resonance in medicine
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更新日期:1988-08-01 00:00:00
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journal_title:Magnetic resonance in medicine
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更新日期:2020-07-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 杂志文章
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更新日期:1994-06-01 00:00:00
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journal_title:Magnetic resonance in medicine
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更新日期:2013-05-01 00:00:00
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journal_title:Magnetic resonance in medicine
pub_type: 临床试验,杂志文章
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更新日期:2006-09-01 00:00:00
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journal_title:Magnetic resonance in medicine
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更新日期:2011-12-01 00:00:00