The acceleration in Parallel MRI is achieved by reducing the number of phase encode steps during data acquisition. SENSE is a Parallel MRI algorithm which reconstructs the fully sampled MR images. Standard SENSE is limited by the noise amplification especially for higher acceleration factors. The *g*-Factor represents the noise amplification during the process of image reconstruction and it varies from pixel-to-pixel. Regularization based SENSE reconstruction uses prior knowledge to improve the quality of the reconstructed image. A method based on the use of *g*-Factor as a regularization parameter in the Tikhonov regularized SENSE reconstruction is proposed. The results show significant improvement in the reconstructed images and computation time. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part A, 2015.

For half a century, pulsed-gradient Spin-Echo NMR based on the Stejskal–Tanner equation has been used to infer Fick's-Law diffusion coefficients of solutes in simple liquids and complex fluids. The decades since the original papers have seen vast advances in instrument technology and pulse sequence design, all leading to improved measurements of diffusion coefficients. However, just as the last half-century has brought major advances in instrument technology, so also it has also brought major advances in scientific understanding of diffusion on molecular distance and time scales. This article discusses implications of these advances in molecular hydrodynamics for the interpretation of PGSE NMR attenuation curves. The results here are particularly significant for studies on complex fluid systems that have relaxations on the time and distance scales that are observed in PGSE NMR experiments. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part A 43A: 1–15, 2015.

]]>Characterization of intrinsically disordered proteins (IDPs) has grown tremendously over the past two decades. NMR-based structural characterization has been widely embraced by the IDP community, largely because this technique is amenable to highly flexible biomolecules. Particularly, carbon-detect nuclear magnetic resonance (NMR) experiments provide a straight forward and expedient method for completing backbone assignments, thus providing the framework to study the structural and dynamic properties of IDPs. However, these experiments remain unfamiliar to most NMR spectroscopists, thus limiting the breadth of their application. In an effort to remove barriers that may prevent the application of carbon-detected bio-NMR where it has the potential to benefit investigators, here we describe the experimental requirements to collect a robust set of carbon-detected NMR data for complete backbone assignment of IDPs. Specifically, we advocate the use of three-dimensional experiments that exploit magnetization transfer pathways initiated on the aliphatic protons, which produces increased sensitivity and provides a suitable method for IDPs that are only soluble in basic pH conditions (>7.5). The applicability of this strategy to systems featuring a high degree of proline content will also be discussed. © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part A 43A: 54–66, 2015.

]]>By the multiple correlation function (MCF) formalism, the nuclear magnetic resonance magnetization of diffusing spins can be represented for simple pore geometries. It may be used to infer geometric structure at the scale of microns. This is to be compared to the diffusion tensor imaging, which provides geometric information at the scale of millimeters. The MCF formulation was derived to special cases in which the gradients of the magnetic field are oriented in specific directions. A generalized approach allowing an arbitrary magnetic field direction was introduced by Özarslan. In this article, we present a complete account of the generalized MCF mathematical derivation starting from Bloch–Torrey equations. It is aimed to the experts and novices alike. We present two approaches—the indirect derivation is based on Özarslan's work, where the standard MCF equations are adopted to arbitrary gradient directions. Our alternative approach is based on direct calculations of the MCF matrices for specified gradient directions. We prove that the two approaches lead to the same equations. Finally, we revise Mitra's microscopic approach and show the relation to the macroscopic MCF approach. We prove that in some limit conditions the two signal equations coincide © 2015 Wiley Periodicals, Inc. Concepts Magn Reson Part A 43A: 16–53, 2015.

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