Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine
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To evaluate monoexponential, stretched exponential, kurtosis, and biexponential models for diffusion-weighted imaging (DWI) of normal prostate and prostate cancer (PCa), using b-values up to 2000 s/mm(2) , in terms of fitting quality and repeatability. ⋯ Considering the model fit and repeatability, the kurtosis model seems to be the preferred model for characterization of normal prostate and PCa DWI using b-values up to 2000 s/mm(2) .
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Comparative Study
Fourier decomposition pulmonary MRI using a variable flip angle balanced steady-state free precession technique.
Fourier decomposition (FD) is a noninvasive method for assessing ventilation and perfusion-related information in the lungs. However, the technique has a low signal-to-noise ratio (SNR) in the lung parenchyma. We present an approach to increase the SNR in both morphological and functional images. ⋯ Both a gain in SNR and an effective resolution gain in functional lung images can be obtained using the FD method in conjunction with a variable flip angle optimized bSSFP sequence.
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To optimize the white-matter-nulled (WMn) Magnetization Prepared Rapid Gradient Echo (MP-RAGE) sequence at 7 Tesla (T), with comparisons to 3T. ⋯ Optimization and new view ordering enabled MP-RAGE imaging with 0.8-1 mm(3) isotropic spatial resolution in scan times of 5 min with whole brain coverage.
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We report a series of techniques to reliably eliminate artifacts in interleaved echo-planar imaging (EPI) based diffusion-weighted imaging (DWI). ⋯ The integration of the multiband and adaptive Homodyne-MUSE algorithms significantly improves the spatial-resolution, image quality, and scan throughput of interleaved DWI. We expect that the reported reconstruction framework will play an important role in enabling high-resolution DWI for both neuroscience research and clinical uses.
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To perform quantitative susceptibility mapping (QSM) in negligible acquisition time and apply it to measuring iron-rich subcortical gray matter. ⋯ EPI-QSM can be performed in several seconds, which enables expansion of brain iron studies of subcortical gray matter to cases where time is limited and to existing MRI studies that already uses gradient echo EPI.