Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Jul 2009
Time-resolved three-dimensional magnetic resonance digital subtraction angiography without contrast material in the brain: Initial investigation.
To evaluate a novel magnetic resonance (MR) angiography (MRA) of three-dimensional (3D) MR digital subtraction angiography (MRDSA) without contrast material, which is essentially 3D true steady-state free precession (SSFP) with selected inversion recovery (IR) pulse using multiple cardiac phase acquisitions with a short increment delay in the assessment of normal cranial arteries, as a feasibility study before clinical use. ⋯ Time-SLIP 3D MRDSA is a simple method for obtaining hemodynamic information. Although more MR sequence improvement is needed, it can play an important role in assessing cranial arteries without contrast material.
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J Magn Reson Imaging · Jul 2009
Quantitative contrast-enhanced perfusion measurements of the human lung using the prebolus approach.
To investigate dynamic contrast-enhanced MRI (DCE-MRI) for quantification of pulmonary blood flow (PBF) and blood volume (PBV) using the prebolus approach and to compare the results to the global lung perfusion (GLP). ⋯ The prebolus approach enables independent determination of appropriate doses for AIF and tissue signal. Using this technique, the signal-to-noise ratio (SNR) from lung parenchyma can be increased, resulting in improved PBF and PBV quantification, which is especially useful for the generation of parameter maps.
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J Magn Reson Imaging · Jul 2009
Improved myelin water quantification using spatially regularized non-negative least squares algorithm.
To improve the myelin water quantification in the brain in the presence of measurement noise and to increase the visibility of small focal lesions in myelin-water-fraction (MWF) maps. ⋯ The MWF variability due to the measurement noise can be substantially reduced and the detection of small focal lesions can be improved by using the srNNLS algorithm.
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J Magn Reson Imaging · Jul 2009
Characterization of low-grade gliomas using RGB color maps derived from ADC histograms.
To use normalized apparent diffusion coefficient (nADC) histograms from patients with grade II oligodendroglioma (OD) and astrocytoma (AC) to generate RGB color maps that emphasize the differences between normal-appearing white matter (NAWM), oligo-like, and astro-like regions. ⋯ This technique allows for the visualization of biologically different regions within the whole tumor mass, which may aid in directing image-guided biopsies. This can be used to ensure that the biopsy is directed to regions that can more accurately define the dominant tumor characteristics.
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J Magn Reson Imaging · Jun 2009
Multiecho time-resolved acquisition (META): a high spatiotemporal resolution Dixon imaging sequence for dynamic contrast-enhanced MRI.
To evaluate a new dynamic contrast-enhanced (DCE) imaging technique called multiecho time-resolved acquisition (META) for abdominal/pelvic imaging. META combines an elliptical centric time-resolved three-dimensional (3D) spoiled gradient-recalled echo (SPGR) imaging scheme with a Dixon-based fat-water separation algorithm to generate high spatiotemporal resolution volumes. ⋯ META is a promising high spatiotemporal resolution imaging sequence for capturing the fast dynamics of hyperenhancing hepatic lesions and provides robust fat suppression even at 3T.