Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Aug 2004
Comparative Study Clinical TrialImproved three-dimensional free-breathing coronary magnetic resonance angiography using gadocoletic acid (B-22956) for intravascular contrast enhancement.
To evaluate gadocoletic acid (B-22956), a gadolinium-based paramagnetic blood pool agent, for contrast-enhanced coronary magnetic resonance angiography (MRA) in a Phase I clinical trial, and to compare the findings with those obtained using a standard noncontrast T2 preparation sequence. ⋯ The use of the intravascular contrast agent B-22956 substantially improves both objective and subjective parameters of image quality on high-resolution three-dimensional coronary MRA. The increase in SNR, CNR, and vessel sharpness minimizes current limitations of coronary artery visualization with high-resolution coronary MRA.
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J Magn Reson Imaging · Aug 2004
Comparative StudyFunctional MRI using multiple receiver coils: BOLD signal changes and signal-to-noise ratio for three-dimensional-PRESTO vs. single shot EPI in comparison to a standard quadrature head coil.
To compare the performance of single shot echo planar imaging (SSEPI) with three-dimensional-multishot echo-planar imaging (EPI) based on principles-of-echo-shifting-with-a-train-of-observations (PRESTO) in combination with a standard quadrature head coil and, as an alternative, a multiple receiver coil in intraoperative functional magnetic resonance imaging (fMRI). ⋯ SSEPI was superior due to its better SNR and a higher BOLD signal change in the defined settings, irrespective of the coil used. In a stereotactical setup the phased array coil can be used to generate fMRI data without loss of image quality.
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J Magn Reson Imaging · Aug 2004
MRI of helium-3 gas in healthy lungs: posture related variations of alveolar size.
To probe the variation of alveolar size in healthy lung tissue as a function of posture using diffusion-weighted helium-3 hyperpolarized gas imaging. ⋯ The posture dependent variations in ADC were attributed to compression of the parenchyma under its own weight and the mass of the heart.
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J Magn Reson Imaging · Aug 2004
Comparative StudyMyocardial delayed enhancement imaging using inversion recovery single-shot steady-state free precession: initial experience.
To evaluate the feasibility of using an inversion recovery single-shot steady-state free precession (SS_SSFP) sequence for myocardial delayed enhancement (MDE) imaging, and to compare SS_SSFP with the conventional inversion recovery segmented fast gradient echo (IR_FGRE) technique. ⋯ SS_SSFP provides adequate image quality compared to IR_FGRE, while requiring a much shorter acquisition time. It is feasible to use SS_SSFP as an alternative method for MDE imaging, especially in patients who have difficulty with holding their breath.
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J Magn Reson Imaging · Aug 2004
Image construction methods for phased array magnetic resonance imaging.
To study image construction in phased array magnetic resonance imaging (MRI) systems from a statistical signal processing point of view. ⋯ It is demonstrated that phased array MRI reconstruction performance can be improved by the use of more elaborate statistical signal processing algorithms.