Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Aug 2010
3D flow-independent peripheral vessel wall imaging using T(2)-prepared phase-sensitive inversion-recovery steady-state free precession.
To develop a 3D flow-independent peripheral vessel wall imaging method using T(2)-prepared phase-sensitive inversion-recovery (T(2)PSIR) steady-state free precession (SSFP). ⋯ T(2)PSIR SSFP is a promising technique for peripheral vessel wall imaging. It provides excellent blood signal suppression and vessel wall/lumen contrast. It can cover a 3D volume efficiently and is flow- and TI-independent.
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J Magn Reson Imaging · Aug 2010
Noise analysis for 3-point chemical shift-based water-fat separation with spectral modeling of fat.
To model the theoretical signal-to-noise ratio (SNR) behavior of 3-point chemical shift-based water-fat separation, using spectral modeling of fat, with experimental validation for spin-echo and gradient-echo imaging. The echo combination that achieves the best SNR performance for a given spectral model of fat was also investigated. ⋯ The optimal echo combination that provides the best SNR performance for water using spectral modeling of fat is very similar to previous optimizations that modeled fat as a single peak. Therefore, the optimal echo spacing commonly used for single fat peak models is adequate for most applications that use spectral modeling of fat.
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J Magn Reson Imaging · Aug 2010
Effects of gradient non-linearity correction and intensity non-uniformity correction in longitudinal studies using structural image evaluation using normalization of atrophy (SIENA).
To evaluate the effects of gradient nonlinearity correction and intensity nonuniformity correction on longitudinal (two-year) changes in global and regional brain volumes. ⋯ Correction for gradient nonlinearity and intensity nonuniformity reduces the variance of measured longitudinal changes in brain volumes and will improve accuracy for detecting subtle brain changes.
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J Magn Reson Imaging · Aug 2010
Impact of motion on T1 mapping acquired with inversion recovery fast spin echo and rapid spoiled gradient recalled-echo pulse sequences for delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) in volunteers.
To evaluate the impact of motion on T1 values acquired by using either inversion-recovery fast spin echo (IR-FSE) or three-dimensional (3D) spoiled gradient recalled-echo (SPGR) sequences for delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) in volunteers. ⋯ Involuntary motion has a significant influence on T1 values acquired with IR-FSE, but not with 3D-SPGR in healthy volunteers.