Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Apr 2007
Measurement of liver fat content using selective saturation at 3.0 T.
To validate an MRI technique for measuring liver fat content by calibrating MRI readings with liver phantoms and comparing MRI measurements in human subjects with estimates of liver fat content on liver biopsy specimens. ⋯ We validated a technique for quantifying liver fat content based on selective fat and water imaging. The technique is accurate and reproducible and provides a noninvasive method to obtain serial measurements of liver fat content in human subjects.
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J Magn Reson Imaging · Apr 2007
Submillimeter isotropic resolution carotid wall MRI with swallowing compensation: imaging results and semiautomated wall morphometry.
To assess a swallowing-compensated, three-dimensional (3D) diffusion-prepared segmented steady-state free precession (3D Nav-D-SSFP) technique for carotid wall MRI with 0.6-mm isotropic spatial resolution, and its utility for semiautomated carotid wall morphometry. ⋯ 3D Nav-D-SSFP is a time-efficient, swallowing-compensated, black-blood technique that lends itself for semiautomated measurements of carotid WA and LA that are in good agreement with manual measurements.
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J Magn Reson Imaging · Mar 2007
Precision, signal-to-noise ratio, and dose optimization of magnitude and phase arterial input functions in dynamic susceptibility contrast MRI.
To determine optimal conditions for precise measurement of arterial input function (AIFs) in dynamic susceptibility contrast (DSC) perfusion MRI. ⋯ AIF SNR is affected most by signal type, then dosing, and lastly, SNR(I(0)).
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J Magn Reson Imaging · Mar 2007
Randomized Controlled Trial Comparative StudyDose comparison of single- vs. double-dose in contrast-enhanced magnetic resonance angiography of the carotid arteries: Intraindividual cross-over blinded trial using Gd-DTPA.
To compare the intraindividual differences of single-dose (D(S)) and double-dose (D(D)) gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA)-enhanced magnetic resonance angiography (MRA) in the carotid arterial territory, an open-label single-center trial with blinded evaluations by two independent radiologists was undertaken. ⋯ Our results demonstrate that while a double dosing of contrast agent does increase SNR, it does not lead to further improvement in visual and perceptual image quality. A single dosage of approximately 0.1 mmol/kg body weight (bw) Gd-DTPA may be the preferable dosage in the carotid arteries.
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To combine gradient-echo (GRE) imaging with a multipoint water-fat separation method known as "iterative decomposition of water and fat with echo asymmetry and least squares estimation" (IDEAL) for uniform water-fat separation. Robust fat suppression is necessary for many GRE imaging applications; unfortunately, uniform fat suppression is challenging in the presence of B(0) inhomogeneities. These challenges are addressed with the IDEAL technique. ⋯ IDEAL-SPGR provides robust water-fat separation with optimized SNR performance at both 1.5T and 3.0T with multicoil acquisitions and parallel imaging in multiple regions of the body.