MWF of the corpus callosum is a robust measure of remyelination: Results from the ReBUILD trial.

Myelin repair is an unrealized therapeutic goal in the treatment of multiple sclerosis (MS). Uncertainty remains about the optimal techniques for assessing therapeutic efficacy and imaging biomarkers are required to measure and corroborate myelin restoration. We analyzed myelin water fraction imaging from ReBUILD, a double-blind, randomized placebo-controlled (delayed treatment) remyelination trial, that showed a significant reduction in VEP latency in patients with MS.

Origin of orientation-dependent R (=1/T ) relaxation in white matter.

Purpose: In a recent MRI study, it was shown that the longitudinal relaxation rate, R , in white matter (WM) is influenced by the relative orientation of nerve fibers with respect to the main magnetic field (B ). Even though the exact nature of this R orientation dependency is still unclear, it can be assumed that the origin of the phenomenon can be attributed to the anisotropic and unique molecular environment within the myelin sheath surrounding the axons. The current work investigates the contribution of dipolar induced R relaxation of the myelin associated hydrogen nuclei theoretically and compares the results with the experimentally observed R orientation dependency.

Dipolar induced spin-lattice relaxation in the myelin sheath: A molecular dynamics study.

Interactions between hydrogen protons of water molecules and macromolecules within the myelin sheath surrounding the axons are a major factor influencing the magnetic resonance (MR) contrast in white matter (WM) regions. In past decades, several studies have investigated the underlying effects and reported a wide range of R rates for the myelin associated compartments at different field strengths. However, it was also shown that the experimental quantification of the compartment-specific R rates is associated with large uncertainties.

Multivariate Platelet Analysis Differentiates Between Patients with Alzheimer's Disease and Healthy Controls at First Clinical Diagnosis.

Background: Early diagnosis of Alzheimer's disease (AD) is challenging, and easily accessible biomarkers are an unmet need. Blood platelets frequently serve as peripheral model for studying AD pathogenesis and might represent a reasonable biomarker source.

Objective: In the present study, we investigated the potential to differentiate AD patients from healthy controls (HC) based on blood count, platelet morphology, and function as well as molecular markers at the time of first clinical diagnosis.

Fibre-orientation dependent R(=1/T) relaxation in the brain: The role of susceptibility induced spin-lattice relaxation in the myelin water compartment.

We have recently observed a dependence of the longitudinal relaxation rate, R, on the orientation of nerve fibres with respect to the main magnetic field. A similar dependence of R is long established and can be well explained by spin-dephasing in an inhomogeneous magnetic field induced by the susceptibility shift between myelin and water protons. The current study investigates if the same effect can also explain the R dependence, neglecting a possible directional dependence of magnetisation transfer between solid myelin and myelin water.

Multivariate prediction of multiple sclerosis using robust quantitative MR-based image metrics.

Objectives: The current work investigates the performance of different multivariate supervised machine learning models to predict the presence or absence of multiple sclerosis (MS) based on features derived from quantitative MRI acquisitions. The performance of these models was evaluated for images which are significantly degraded due to subject motion, a problem which is often observed in clinical routine diagnostics. Finally, the difference between a true multivariate analysis and the corresponding univariate analysis based on single parameters alone was addressed.

The impact of fibre orientation on T-relaxation and apparent tissue water content in white matter.

Objective: Recent MRI studies have shown that the orientation of nerve fibres relative to the main magnetic field affects the R*(= 1/T*) relaxation rate in white matter (WM) structures. The underlying physical causes have been discussed in several studies but are still not completely understood. However, understanding these effects in detail is of great importance since this might serve as a basis for the development of new diagnostic tools and/or improve quantitative susceptibility mapping techniques.

Fractal and Euclidean descriptors of platelet shape.

Platelet shape change is a dynamic membrane surface process that exhibits remarkable morphological heterogeneity. Once the outline of an irregular shape is identified and segmented from a digital image, several mathematical descriptors can be applied to numerical characterize the irregularity of the shapes surface. 13072 platelet outlines (PLO) were segmented automatically from 1928 microscopic images using a newly developed algorithm for the software product Matlab R2012b.

Multicentre absolute myelin water content mapping: Development of a whole brain atlas and application to low-grade multiple sclerosis.

The current study investigates the whole brain myelin water content distribution applying a new approach that allows for the simultaneous mapping of total and relative myelin water content, T 1 and T 2* with full brain coverage and high resolution (1 × 1 × 2 mm(3)). The data was collected at two different sites in healthy controls to validate the independence of a specific setup. In addition, a group of patients with known white matter affections was investigated to compare two measures of myelin, i.

Rapid myelin water content mapping on clinical MR systems.

We present an algorithm for the fast mapping of myelin water content using standard multiecho gradient echo acquisitions of the human brain. The method extents a previously published approach for the simultaneous measurement of brain T(1), T(2)(*) and total water content. Employing the multiexponential T(2)(*) decay signal of myelinated tissue, myelin water content was measured based on the quantification of two water pools ("myelin water" and "rest") with different relaxation times.

Fully-automated detection of cerebral water content changes: study of age- and gender-related H2O patterns with quantitative MRI.

We present a simple and robust method for the automated image analysis of quantitative cerebral water content maps acquired with MRI. The method is based on a new approach for the absolute and quantitative mapping of water content in vivo. Water content maps were automatically segmented into grey and white matter by employing the quantitative T1 information acquired as part of the water content mapping procedure.

Quantitative T1 mapping of hepatic encephalopathy using magnetic resonance imaging.

Changes are shown in the spin-lattice (T1) relaxation time caused by the putative deposition of manganese in various brain regions of hepatic encephalopathy (HE) patients using a novel and fast magnetic resonance imaging (MRI) method for quantitative relaxation time mapping. A new method, T1 mapping with partial inversion recovery (TAPIR), was used to obtain a series of T1-weighted images to produce T1 maps. Imaging of 15 control subjects and 11 patients was performed on a 1.