X-ray diffraction studies give material-specific information about biological tissue. Ideally, a large area, low noise, wide dynamic range digital x-ray detector is required for laboratory-based x-ray diffraction studies. The goal of this work is to introduce a novel imaging technology, the CMOS active pixel sensor (APS) that has the potential to fulfil all these requirements, and demonstrate i...

We present a novel on-the-fly scatter approximation scheme that can be applied concurrently to multiple volumetric datasets. We use a simplified version of the emission-absorption model, including single scattering and shadowing and guide the scatter sample positions and in-scatter coefficients by local gradients. This allows us to render multiple intersecting volumes with our rendering system ...

UNLABELLED Planar gamma-scintigraphy is often used to quantify pulmonary deposition patterns from aerosol inhalers. The results are quite different from those obtained using 3-dimensional PET and SPECT. The purpose of this study was to characterize the effects of scatter and tissue attenuation on the distribution of radiolabeled aerosol as measured by planar scintigraphy using Monte Carlo simul...

The qualitative and quantitative accuracy of SPECT images is degraded by physical factors of attenuation, Compton scatter and spatially varying collimator geometric response. This paper presents a 3D ray-tracing technique for modelling attenuation, scatter and geometric response for SPECT imaging in an inhomogeneous attenuating medium. The model is incorporated into a three-dimensional projecto...

From the process of scatter-gather algorithm explained above, we can easily find the essence of the parallel version of this algorithm is the parallel clustering algorithm used in the scatter phase. Frieder, et al. implements a parallel version of the buckshot clustering algorithm [1]. Their work meets the need of the parallel scatter-gather clustering algorithm pretty well, although we can des...

We examine coding strategies for coded aperture scatter imagers. Scatter imaging enables tomography of compact regions from snapshot measurements. We present coded aperture designs for pencil and fan beam geometries, and compare their singular value spectra with that of the Radon transform and selected volume tomography. We show that under dose constraints scatter imaging improves conditioning ...

In multivariate analysis we often deal with situations involving several populations, such as discriminant analysis, where the assumption of equality of scatter matrices is usually assumed. Yet sometimes, this assumption is not adequate but problems related to an excessive number of parameters will arise if we estimate the scatter matrices separately for each population. In many practical situa...

OBJECTIVE Positron emission tomography (PET) enables quantitative measurements of various biological functions. Accuracy in data acquisition and processing schemes is a prerequisite for this. The correction of scatter is especially important when a 3D PET scanner is used. The aim of this study was to validate the use of a simplified calculation-based scatter correction method for 15O studies in...

Well-known radar scattering mechanisms are Rayleigh scattering (incoherent particle scattering), and clear-air scattering (coherent air scattering). This article discusses the importance in clouds of these two mechanisms compared to a third scattering mechanism: coherent particle scattering, which is caused by spatial variations in the liquid water content of the clouds. We will argue that for ...

Planar g-scintigraphy is often used to quantify pulmonary deposition patterns from aerosol inhalers. The results are quite different from those obtained using 3-dimensional PET and SPECT. The purpose of this study was to characterize the effects of scatter and tissue attenuation on the distribution of radiolabeled aerosol as measured by planar scintigraphy using Monte Carlo simulations. This st...