Introduction: Echo volumar imaging (EVI) is a 3D extension of echo-planar imaging (EPI) that allows data from an entire volume to be acquired following a single excitation. However, only a few studies to date have applied EVI to functional MRI (fMRI) due to its high sensitivity to field-inhomogeneity induced distortions. In this study, we extend two EPI distortion correction techniques to EVI: ...

We report construction of a portable nuclear magnetic resonance sensor with a single-sided open probe design. The resulting magnetic field inhomogeneity is compensated by a pulse sequence that takes advantage of parallel inhomogeneity in the applied radio frequency field. We can thereby acquire fluorine-19 spectra of liquid fluorocarbons with 8 parts per million resolution, surmounting the long...

The accurate and effective algorithm for segmenting image is very useful in many fields, especially in medical image. In this paper we introduced a novel method that focus on segmenting the brain MR Image that is important for neural diseases. Because of many noises embedded in the acquiring procedure, such as eddy currents, susceptibility artifacts, rigid body motion, and intensity inhomogenei...

Detecting inhomogeneity in a turbid tissue using optical tomography technique as a non-invasive tool is of paramount importance in imaging and diagnosis of diseases and tissue abnormalities. In our approach, an ultrafast laser is used as the detecting source and the backscattered light signals are collected around the boundary of the target. We have developed a Monte Carlo program used to simul...

−A systematic formulation of constitutive relations for general field systems is explored, which takes into account the main material features. These are dispersion, inhomogeneity, which can be present in linear and nonlinear systems. There are two main difficulties associated with existing representations: Dispersion is usually referred to in the spectral domain, while inhomogeneity is obvious...

In this paper, a new method for detecting inhomogeneity in turbid media is proposed and investigated both numerically and experimentally. An ultrafast laser, whose pulse width is in the range of picoseconds or femtoseconds, is used as the detecting source and backscattered light signals are collected around the boundary of the target. This novel technique that we used to locate inhomogeneity is...

Unidirectional (24)Na fluxes across the dog red blood cell membrane were measured. The kinetics were incompatible with a single time constant but could be accounted for in terms of a two-series compartment cell model, with approximately 1% of cell Na in the outer compartment. Dog red blood cells are known to be inhomogeneous in their Na and K permeabilities. Theoretical analysis showed that suc...

We consider a singularly perturbed bistable reaction diffusion equation in a one-dimensional spatially degenerate inhomogeneous media. Degeneracy arises due to the choice of spatial inhomogeneity from some well-known class of normal forms or universal unfoldings. By means of a bilinear double well potential, we explicitly demonstrate the similarities and discrepancies between the bifurcation ph...