Abstract:
:Measurements have been carried out in six subjects at magnetic fields of 1.5, 3 and 7 T, with the aim of characterizing the variation of T2* with field strength in human brain. Accurate measurement of T2* in the presence of macroscopic magnetic field inhomogeneity is problematic due to signal decay resulting from through-slice dephasing. The approach employed here allowed the signal decay due to through-slice dephasing to be characterized and removed from data, thus facilitating an accurate measurement of T2* even at ultrahigh field. Using double inversion recovery turbo spin-echo images for tissue classification, an analysis of T2* relaxation times in cortical grey matter and white matter was carried out, along with an evaluation of the variation of T2* with field strength in the caudate nucleus and putamen. The results show an approximately linear increase in relaxation rate R2* with field strength for all tissues, leading to a greater range of relaxation times across tissue types at 7 T that can be exploited in high-resolution T2*-weighted imaging.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Peters AM,Brookes MJ,Hoogenraad FG,Gowland PA,Francis ST,Morris PG,Bowtell Rdoi
10.1016/j.mri.2007.02.014subject
Has Abstractpub_date
2007-07-01 00:00:00pages
748-53issue
6eissn
0730-725Xissn
1873-5894pii
S0730-725X(07)00170-1journal_volume
25pub_type
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