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Susceptibility-weighted imaging (SWI) is a new neuroimaging technique, which uses tissue magnetic susceptibility differences to generate a unique contrast, different from that of spin density, T1, T2, and T2*. In this review (the first of 2 parts), we present the technical background for SWI. We discuss the concept of gradient-echo images and how we can(More)
PURPOSE To create an orientation-independent, 3D reconstruction of the veins in the brain using susceptibility mapping. MATERIALS AND METHODS High-resolution, high-pass filtered phase images usually used for susceptibility weighted imaging (SWI) were used as a source for local magnetic field behavior. These images were subsequently postprocessed using an(More)
PURPOSE The botanical formulation, PHY906, has been used widely in Eastern countries to treat gastrointestinal symptoms including diarrhea, nausea and vomiting. PHY906 may also have anti-tumor properties and may potentiate the action of several chemotherapeutic agents based on pre-clinical studies. We conducted a Phase I study using PHY906 in combination(More)
The appropriate choice of resolution in fMRI remains an open question. To address this issue, we simulate the signal change between activated and resting states as a function of blood volume fraction (lambda). From these results, the relative contrast-to-noise ratio (CNR) from the resting to the activated state can be calculated as a function of resolution.(More)
To improve susceptibility quantification, a threshold-based k-space/image domain iterative approach that uses geometric information from the susceptibility map itself as a constraint to overcome the ill-posed nature of the inverse filter is introduced. Simulations were used to study the accuracy of the method and its robustness in the presence of noise. In(More)
We present an analytical form for the density of states for a magnetic dipole in the center of a spherical voxel. This analytic form is then used to evaluate the signal decay as a function of echo time for different volume fractions and susceptibilities. The decay can be considered exponential only in a limited interval of time. Otherwise, it has a(More)
The low magnification performance of a Philips CM300-FEG transmission electron microscope was characterized in three different configurations: CM30-FEG Super Twin, CM30-FEG Twin and CM300-FEG Cryo Twin. Micrographs of gold single crystal, polycrystalline gold, graphitized carbon and copper chloropthalocyanine were recorded in the magnification range(More)
A method based on Fourier transforms is described for obtaining a 3-D reconstruction from a paracrystalline object with static disorder. The method is derived from the standard methods used in 3-D reconstruction of 2-D crystals except that all of the Fourier coefficients are used and not just the sampled data from the periodic lattice. Thus, not only is the(More)
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