Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Oct 2014
Ultrafast volumetric B1 (+) mapping for improved radiofrequency shimming in 3 tesla body MRI.
To evaluate the use of the recently proposed ultrafast B1 (+) mapping approach DREAM (Dual Refocusing Echo Acquisition Mode) for a refinement of patient adaptive radiofrequency (RF) shimming. ⋯ Volumetric information about B1 (+) can be used to further improve the accuracy and homogeneity of the B1 (+) field yielding higher diagnostic confidence, and will also be of value for various quantitative methods which are sensitive to flip angle imperfections.
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J Magn Reson Imaging · Oct 2014
Dielectric pads and low- B1+ adiabatic pulses: complementary techniques to optimize structural T1 w whole-brain MP2RAGE scans at 7 tesla.
To evaluate the combination of low-B1 (+) adiabatic pulses and high permittivity (εr ≈ 165) dielectric pads effectiveness to reproducibly improve the inversion efficiency for whole-brain MP2RAGE scans, at ultra-high field. ⋯ The complementary techniques of low-B1 (+) adiabatic RF pulses and high permittivity dielectric pads allow whole-brain structural T1 w images to be reliably acquired at ultra-high field. J. Magn. Reson. Imaging 2014;40:804-812. © 2013 Wiley Periodicals, Inc.
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J Magn Reson Imaging · Oct 2014
Comparative StudyRapid isotropic resolution cartilage assessment using radial alternating repetition time balanced steady-state free-precession imaging.
To compare a balanced steady-state free-precession sequence with a radial k-space trajectory and alternating repetition time fat suppression (Radial-ATR) with other currently used fat-suppressed 3D sequences for evaluating the articular cartilage of the knee joint at 3.0T. ⋯ Radial-ATR had superior SNR efficiency to other fat-suppressed 3D cartilage imaging sequences and produced high isotropic resolution images of the knee joint which could be used for evaluating articular cartilage at 3.0T.
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J Magn Reson Imaging · Oct 2014
Comparative Study Controlled Clinical TrialQuantitative evaluation of liver function with T1 relaxation time index on Gd-EOB-DTPA-enhanced MRI: comparison with signal intensity-based indices.
To evaluate whether the reduction rate of T1 relaxation time of the liver (T1 relaxation time index) before and 20 minutes after gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) injection has the potential to serve as an magnetic resonance imaging (MRI)-based liver function test in comparison with signal intensity-based indices. ⋯ The T1 relaxation time index has the potential to serve as an MRI-based liver function test, and is most strongly correlated with ICG clearance among the Gd-EOB-DTPA MRI-based indices investigated.
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To: 1) Present fornix tractography in its entirety for 20 healthy individuals to assess variability. 2) Provide individual and groupwise whole tract diffusion parameter symmetry assessments prior to clinical application. 3) Compare whole tract diffusion parameter assessments with tract-based spatial statistics (TBSS). ⋯ The findings demonstrate consistency of fornix tractography as well as some variability in the columns and fimbria. While parametric assessment demonstrates diffusion parameter symmetry, permutation-based TBSS analysis reveals significant FA asymmetries in the crura and fimbriae.