Journal of magnetic resonance imaging : JMRI
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J Magn Reson Imaging · Dec 2014
Comparative StudyVariable spatiotemporal resolution three-dimensional Dixon sequence for rapid dynamic contrast-enhanced breast MRI.
To investigate a new variable spatiotemporal resolution dynamic contrast-enhanced (DCE) MRI method termed DIfferential Subsampling with Cartesian Ordering (DISCO), for imaging of breast cancer. ⋯ DISCO is a promising variable-spatiotemporal-resolution imaging sequence for capturing the dynamics of rapidly enhancing tumors as well as structural features postcontrast. A near 1-mm isotropic spatial resolution was achieved with postcontrast static phase images in 120 s and dynamic phase images acquired in 9 s per phase.
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J Magn Reson Imaging · Dec 2014
Relationship of MR elastography determined liver stiffness with cardiac function after Fontan palliation.
To use MR elastography to assess liver stiffness in patients with congenital heart disease palliated with the Fontan procedure and correlate findings with cardiac index and other functional parameters obtained during cardiac MRI. ⋯ MRE shows promise as a monitoring tool in the Fontan population, demonstrating an elevated liver stiffness in all patients, which inversely correlated with the MR determined cardiac index.
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J Magn Reson Imaging · Dec 2014
Practical estimate of gradient nonlinearity for implementation of apparent diffusion coefficient bias correction.
To describe an efficient procedure to empirically characterize gradient nonlinearity and correct for the corresponding apparent diffusion coefficient (ADC) bias on a clinical magnetic resonance imaging (MRI) scanner. ⋯ Empiric scalar adjustment of an independent gradient nonlinearity model adequately described DWI bias for a clinical scanner. Observed efficiency of implemented ADC bias correction quantitatively agreed with previous theoretical predictions and numerical simulations. The described procedure provides an independent benchmark for nonlinearity bias correction of clinical MRI scanners.
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J Magn Reson Imaging · Dec 2014
Rapid single-breath-hold 3D late gadolinium enhancement cardiac MRI using a stack-of-spirals acquisition.
To develop a rapid single-breath-hold 3D late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) method, and demonstrate its feasibility in cardiac patients. ⋯ Stack-of-spiral acquisition combined with non-Cartesian SPIRiT parallel imaging enables rapid 3D LGE MRI in a 12 heartbeat-long breath-hold.J.
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J Magn Reson Imaging · Dec 2014
Short-term exercise-induced changes in hydration state of healthy Achilles tendons can be visualized by effects of off-resonant radiofrequency saturation in a three-dimensional ultrashort echo time MRI sequence applied at 3 Tesla.
Off-resonant RF saturation influences signal intensity dependent on free and bound water fractions as well as the macromolecular content. The extent of interaction between these compartments can be evaluated by using the off-resonance saturation ratio (OSR). Combined with UTE sequences quantification of OSR even in tendinous tissues with extremely fast signal decay is possible. The aim of this prospective study was to investigate short-term exercise-induced effects of hydration state of the Achilles tendon by means of OSR and tendon volume. ⋯ The observed decreased tendon volume and increased OSR directly after exercise indicates a short-term change in tendinous proton compartments, most likely a loss of free water molecules within the tendon.