Linked Life Data

1461121

Source:http://linkedlifedata.com/resource/pubmed/id/1461121

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-1-8
pubmed:abstractText
A theoretical algorithm for shaping the signal response during the approach to steady state in three-dimensional magnetization-prepared rapid gradient-echo (3D MP-RAGE) pulse sequences has been developed and implemented. This algorithm derives the flip angle series required to produce specifically chosen time evolutions of the signal intensities during the data acquisition segment of 3D MP-RAGE sequences. Theoretical predictions for the cases of unshaped, uniform, and mono-exponential decay signal responses were quantitatively validated with a doped-water phantom on a 1.5-T whole-body imager and in all cases there was excellent agreement between the theoretical and experimental values. The effects of RF inhomogeneities and eddy currents on the signal response shaping were also investigated. To demonstrate the potential utility of the technique, the signal response shaping algorithm was applied to a T1-weighted 3D MP-RAGE sequence to derive the acquisition flip angle series which theoretically yields the maximum white matter/gray matter signal difference (WGSD) consistent with the chosen response shape. Images obtained from a healthy volunteer using this variable flip angle sequence were compared with 3D RF-spoiled steady-state gradient-echo images obtained in the same total imaging time. The 3D MP-RAGE images demonstrated a 41% increase in the WGSD-to-noise ratio. These initial very promising results indicate that with further refinement to eliminate some intensity artifacts, the variable flip angle 3D MP-RAGE technique may, with respect to certain image properties, provide considerable improvements over currently available 3D gradient-echo imaging techniques.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0740-3194
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
165-85
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Shaping the signal response during the approach to steady state in three-dimensional magnetization-prepared rapid gradient-echo imaging using variable flip angles.
pubmed:affiliation
Department of Radiology, University of Virginia Health Sciences Center, Charlottesville.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't