Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jan 2008
Renal T2-weighted turbo-spin-echo imaging with BLADE at 3.0 Tesla: initial experience.
The purpose of this study is to evaluate the feasibility and image quality of multishot T2-weighted (T2w) renal morphologic imaging based on the acquisition of rotating rectangular strips of k-space data after successive radiofrequency excitations (BLADE technique). ⋯ The SNR did not show significant differences. The overall image quality was rated significantly higher for the T2w-BLADE (P < 0.05). Equally, the presence of disturbing artifacts and the sharpness was ranked significantly better for T2w-BLADE than for the T2w-TSE (P < 0.05). The T2w-BLADE was the preferred sequence in 59% of all cases, the T2w-TSE in 9%.T2w-BLADE sequences seem to be superior for the depiction of the kidneys at 3.0T, particularly due to the decreased number of artifacts and sharper delineation of the organs.
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J Magn Reson Imaging · Jan 2008
Automatic correction of echo-planar imaging (EPI) ghosting artifacts in real-time interactive cardiac MRI using sensitivity encoding.
To develop a method that automatically corrects ghosting artifacts due to echo-misalignment in interleaved gradient-echo echo-planar imaging (EPI) in arbitrary oblique or double-oblique scan planes. ⋯ The proposed technique with nonaccelerated acquisition provides excellent ghost suppression in arbitrary scan orientations without a calibration scan, and can be useful for real-time interactive imaging, in which scan planes are frequently changed with arbitrary oblique orientations.
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J Magn Reson Imaging · Dec 2007
Multiparametric differentiation of posterior fossa tumors in children using diffusion-weighted imaging and short echo-time 1H-MR spectroscopy.
To assess the combined value of diffusion-weighted imaging (DWI) and proton magnetic resonance spectroscopy (1H-MRS) in differentiating medulloblastoma, ependymoma, pilocytic astrocytoma, and infiltrating glioma in a pediatric population. ⋯ Linear discriminant analysis using DWI and MRS using water as internal reference, fully discriminates the four most frequent posterior fossa tumors in children.
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J Magn Reson Imaging · Dec 2007
Correlation of lung parenchymal MR signal intensity with pulmonary function tests and quantitative computed tomography (CT) evaluation: a pilot study.
To evaluate the effect of ventilatory impairment on MR signal intensity of the lung parenchyma. ⋯ In COPD patients, lung signal change measured by MRI correlates with airflow obstruction, but not with volume of the emphysema measured by lung CT.
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J Magn Reson Imaging · Dec 2007
Detecting groups of coherent voxels in functional MRI data using spectral analysis and replicator dynamics.
To investigate the relationship between functional MRI (fMRI) time series in the human brain, combining fMRI spectral analysis and replicator dynamics. ⋯ The application of replicator dynamics to spectral matrices is a reliable method for detecting groups of maximally coherent voxels. A replicator process is able to determine groups of voxels with the property that each voxel in the group exhibits a high coherence with every other group member. In contrast to the NCV approach, this method is parameter-free and does not require the a priori selection of a reference voxel.