Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Oct 2007
Interleaved water and fat imaging and applications to lipid quantitation using the gradient reversal technique.
To implement and evaluate the gradient reversal-based chemical shift imaging technique to obtain qualitative and quantitative spatially-registered fat and water images with high imaging efficiency at very high field. ⋯ The proposed MRI technique permits interleaved water and fat imaging, with which spectrally well-separated water and fat images at the identical slice locations could be obtained in a single acquisition without increasing scan time. The technique could be used for in vivo quantitative mapping of lipid content and applied to investigations using small animal experiment models.
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J Magn Reson Imaging · Oct 2007
Optimization and validation of a fully-integrated pulse sequence for modified look-locker inversion-recovery (MOLLI) T1 mapping of the heart.
To optimize and validate a fully-integrated version of modified Look-Locker inversion-recovery (MOLLI) for clinical single-breathhold cardiac T1 mapping. ⋯ We present an optimized implementation of MOLLI for fast T1 mapping with high spatial resolution, which can be integrated into routine imaging protocols. T1 accuracy is superior to the original set of pulse sequence parameters and heart rate dependency is avoided.
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J Magn Reson Imaging · Oct 2007
Comparison of region-of-interest analysis with three different histogram analysis methods in the determination of perfusion metrics in patients with brain gliomas.
To compare routine ROI analysis and three different histogram analyses in the grading of glial neoplasms. The hypothesis is that histogram methods can provide a robust and objective technique for quantifying perfusion data in brain gliomas. Current region-of-interest (ROI)-based methods for the analysis of dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC MRI) data are operator-dependent. ⋯ Histogram analysis of perfusion MR provides prediction of glioma grade, with peritumoral metrics outperforming tumoral and total tumoral metrics. Further refinement may lead to automated methods for perfusion data analysis.
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J Magn Reson Imaging · Oct 2007
High-resolution T1 mapping of the brain at 3T with driven equilibrium single pulse observation of T1 with high-speed incorporation of RF field inhomogeneities (DESPOT1-HIFI).
To investigate an alternative approach to correct for flip angle inaccuracies in the driven equilibrium single pulse observation of T1 (DESPOT1) T1 mapping method. ⋯ The described approach, dubbed DESPOT1-HIFI, permits whole-brain T1 mapping at 3T, with 1 mm(3) isotropic voxels, in a clinically feasible time (approximately 10 minutes) with T1 accuracy greater than 5% and with high precision.
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J Magn Reson Imaging · Oct 2007
Quantification of rodent cerebral blood flow (CBF) in normal and high flow states using pulsed arterial spin labeling magnetic resonance imaging.
To implement a pulsed arterial spin labeling (ASL) technique in rats that accounts for cerebral blood flow (CBF) quantification errors due to arterial transit times (dt)-the time that tagged blood takes to reach the imaging slice-and outflow of the tag. ⋯ Even when flow is accelerated, CBF can be accurately determined using pulsed ASL, as long as dt and outflow of the tag are accounted for.