Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine
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To characterize errors in enhancement in breast dynamic contrast-enhanced (DCE) MRI studies as a function of echo time and determine the source of dark band artifacts in clinical subtraction images. ⋯ Errors in expected enhancement occur in DCE breast MRI subtraction images because of differential enhancement of fat and water and incomplete fat signal suppression. These errors can lead to artificial suppression of enhancement as well as dark band artifacts on subtraction images. These artifacts can be eliminated with a time-equivalent in-phase fat-suppressed 3D gradient-recalled echo sequence. Understanding chemical shift artifact of the third kind, a unique artifact of artificial enhancement suppression in the presence of intravoxel fat and water signal, will aid DCE breast MRI image interpretation. In-phase acquisitions (combined with simultaneous minimum echo time or opposed-phase echoes) may facilitate qualitative, quantitative and longitudinal analysis of contrast enhancement. Magn Reson Med 79:2277-2289, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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To develop echo-planar spectroscopic imaging (EPSI) with large spectral width and accomplish high-resolution imaging of 2-hydroxyglutarate (2HG) at 7 T. ⋯ The data indicated that the dual-readout alternated gradients EPSI can provide reliable high-resolution imaging of 2HG in glioma patients at 7 T in vivo. Magn Reson Med 79:1851-1861, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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To compare the fitting and tissue discrimination performance of biexponential, kurtosis, stretched exponential, and gamma distribution models for high b-factor diffusion-weighted images in prostate cancer. ⋯ All models, including a monoexponential fit to a lower-b sub-range, achieve similar AUCs for discrimination of normal and cancer tissue. The biexponential model, which is favored statistically, also appears to provide insight into disease-related microstructural changes. Magn Reson Med 79:2346-2358, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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To develop a new approach to correct for physiological and macroscopic motion in multishot, interleaved echo-planar diffusion imaging. ⋯ The proposed method can effectively correct for physiological and macroscopic motion artifacts in multishot interleaved echo-planar imaging, generate high resolution diffusion images, and improve the accuracy of tensor calculation. Magn Reson Med 79:1992-2002, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Metabolite cycling (MC) is an MRS technique for the simultaneous acquisition of water and metabolite spectra that avoids chemical exchange saturation transfer effects and for which water may serve as a reference signal or contain additional information in functional or diffusion studies. Here, MC was developed for human investigations at ultrahigh field. ⋯ This work introduces a novel methodology for single-voxel MRS on a 9.4T whole-body scanner and highlights the advantages of semi-LASER compared to STEAM in terms of excitation profile. In comparison with MC-STEAM, MC-semi-LASER yields spectra with higher SNR. Magn Reson Med 79:1841-1850, 2018. © 2017 International Society for Magnetic Resonance in Medicine.