Assessment of a diffusion phantom for quality assurance in brain microstructure diffusion MRI studies.

Diffusion-weighted imaging (DWI) is a key contrast mechanism in MRI which allows for the assessment of microstructural properties of brain tissues by measuring the displacement of water molecules. Several diffusion models, including the tensor (DTI), kurtosis (DKI), and neurite orientation dispersion and density imaging (NODDI), are commonly used in both research and clinical practice. However, there is currently no standardized method for validating the stability and repeatability of these models over time.

Evaluation of an integrated variable flip angle protocol to estimate coil B for hyperpolarized MRI.

Purpose: The purpose of this work is to validate a simple and versatile integrated variable flip angle (VFA) method for mapping B in hyperpolarized MRI, which can be used to correct signal variations due to coil inhomogeneity.

Theory And Methods: Simulations were run to assess performance of the VFA B mapping method compared to the currently used constant flip angle (CFA) approach. Simulation results were used to inform the design of VFA sequences, validated in four volunteers for hyperpolarized xenon-129 imaging of the lungs and another four volunteers for hyperpolarized carbon-13 imaging of the human brain.

Enabling SENSE accelerated 2D CSI for hyperpolarized carbon-13 imaging.

As hyperpolarized (HP) carbon-13 (C) metabolic imaging is clinically translated, there is a need for easy-to-implement, fast, and robust imaging techniques. However, achieving high temporal resolution without decreasing spatial and/or spectral resolution, whilst maintaining the usability of the imaging sequence is challenging. Therefore, this study looked to accelerate HP C MRI by combining a well-established and robust sequence called two-dimensional Chemical Shift Imaging (2D CSI) with prospective under sampling and SENSitivity Encoding (SENSE) reconstruction.

Hyperpolarized Carbon 13 MRI: Clinical Applications and Future Directions in Oncology.

Hyperpolarized carbon 13 MRI (C MRI) is a novel imaging approach that can noninvasively probe tissue metabolism in both normal and pathologic tissues. The process of hyperpolarization increases the signal acquired by several orders of magnitude, allowing injected C-labeled molecules and their downstream metabolites to be imaged in vivo, thus providing real-time information on kinetics. To date, the most important reaction studied with hyperpolarized C MRI is exchange of the hyperpolarized C signal from injected [1-C]pyruvate with the resident tissue lactate pool.

Assessing the effect of anesthetic gas mixtures on hyperpolarized C pyruvate metabolism in the rat brain.

Purpose: To determine the effect of altering anesthetic oxygen protocols on measurements of cerebral perfusion and metabolism in the rodent brain.

Methods: Seven rats were anesthetized and underwent serial MRI scans with hyperpolarized [1- C]pyruvate and perfusion weighted imaging. The anesthetic carrier gas protocol used varied from 100:0% to 90:10% to 60:40% O :N O.

The effects of glucose and fatty acids on CXCL10 expression in skeletal muscle cells.

Skeletal muscles produce secretory factors termed as myokines, which alter physiological functions of target tissues. We recently identified C-X-C chemokine ligand 10 (CXCL10) as a novel myokine, which is downregulated in response to exercise. In the present study, we investigated whether the nutritional changes affect CXCL10 expression in mouse skeletal muscle.

A novel GH43 α-l-arabinofuranosidase of Penicillium chrysogenum that preferentially degrades single-substituted arabinosyl side chains in arabinan.

We previously described three α-l-arabinofuranosidases (ABFs) secreted by Penicillium chrysogenum 31B. Here, we purified a fourth ABF, termed PcABF43A, from the culture filtrate. The molecular mass of the enzyme was estimated to be 31kDa.