Partial volume effects are often experienced in diffusion-weighted MRI of biologic tissue. This is when the signal attenuation reflects a mixture of diffusion processes, originating from different tissue compartments, residing in the same voxel. Decomposing the mixture requires elaborated models that account for multiple compartments, yet the fitting problem for those models is usually ill pose...

Diffusion weighted imaging (DWI) is widely used to study microstructural characteristics of the brain. Diffusion tensor imaging (DTI) and high-angular resolution imaging (HARDI) are frequently used in radiology and neuroscience research but can be limited in describing the signal behavior in composite nerve fiber structures. Here, we developed and assessed the benefit of a comprehensive diffusi...

OBJECTIVE: To study the utility of diffusion-weighted magnetic resonance imaging in the differentiation between benign and malignant breast lesions. MATERIALS AND METHODS: Forty-five women (mean age, 46.1 years) with 52 focal breast lesions underwent diffusion-weighted magnetic resonance imaging. The calculation of apparent diffusion coefficient (ADC) was based on the ADC map reflecting five b ...

MR diffusion tensor imaging (DTI) of the brain and spine provides a unique tool for both visualizing directionality and assessing intactness of white matter fiber tracts in vivo. At the spatial resolution of clinical MRI, much of primate white matter is composed of interdigitating fibers. Analyses based on an assumed single diffusion tensor per voxel yield important information about the averag...

Introduction: White matter fiber “tractography” from diffusion MRI data is widely used in the neuroscience community and in clinical research setting to investigate white matter pathways in the human brain. Diffusion weighted images (DWIs) are generally acquired with echo planar (EPI), and suffer from concomitant field [1] and susceptibility related geometrical distortions in the phase encode d...

OBJECTIVE We examine the clinical impetus for whole-body diffusion-weighted MRI and discuss how to implement the technique with clinical MRI systems. We include practical tips and tricks to optimize image quality and reduce artifacts. The interpretative pitfalls are enumerated, and potential challenges are highlighted. CONCLUSION Whole-body diffusion-weighted MRI can be used for tumor staging...

Objective : The aim of this study was to analyse the efficacy of Diffusion Weighted MR Imaging (DWI) and Apparent Diffusion Coefficient (ADC) mapping in the diagnosis of meniscal tears in the knee. Conclusion : DWI and ADC mapping technique are fast and easily applicable with routine MRI sequences and these new MRI techniques (for the knee) depicts very important information for menisci and car...

The significant advances in magnetic resonance imaging (MRI) hardware and software, sequence design, and postprocessing methods have made diffusion-weighted imaging (DWI) an important part of body MRI protocols and have fueled extensive research on quantitative diffusion outside the brain, particularly in the oncologic setting. In this review, we summarize the most up-to-date information on DWI...

Here, M is the magnetization of an excited sample placed in a static magnetic field B0, γ is the gyromagnetic ratio, Mx, My, Mz are the components of magnetization in the x, y and z directions, M0 is the magnetization at thermal equilibrium, T1 and T2 are the longitudinal and transverse relaxation times and D is the diffusion coefficient. The first two terms of Equation 1 are the original Bloch...

We describe and evaluate a pre-processing method based on a periodic spiral sampling of diffusion-gradient directions for high angular resolution diffusion magnetic resonance imaging. Our pre-processing method incorporates prior knowledge about the acquired diffusion-weighted signal, facilitating noise reduction. Periodic spiral sampling of gradient direction encodings results in an acquired si...