background: most preclinical studies are carried out on mice. for internal dose  assessment of a mouse, specific absorbed fraction (saf) values play an important role.  in most studies, saf values are estimated using older standard human organ compositions  and values for limited source target pairs. objective: saf values for monoenergetic photons of energies 15, 50, 100, 500,  1000 and 4000 ke...

The Monte Carlo simulations using the mathematical phantom of a human body model is useful as a method of getting to know the details of the radiation exposure in a human body. However, it is very difficult to evaluate experimentally the validity of the calculation result of the simulation using the human body model. Then, the mathematical phantom of voxel-type (voxel phantom) for the Monte Car...

This report presents a voxel-based biomechanical model for muscle deformation using nite element method (FEM) and volume graphics. Hierarchical voxel meshes are reconstructed from ltered segmented muscle images followed by FEM simulation and volume rendering. Physiological muscle force is considered and linear elastic muscle models for both static and dynamic cases are simulated by FEM. Voxel-b...

A mixture model clustering algorithm is presented for robust MRI brain image segmentation in the presence of partial volume averaging. The method uses additional classes to represent partial volume voxels of mixed tissue type in the data with their probability distributions modeled accordingly. The image model also allows for tissue-dependent variance values and voxel neighborhood information i...

In functional magnetic resonance imaging, voxel time courses after Fourier or non-Fourier “image reconstruction” are complex valued as a result of phase imperfections due to magnetic field inhomogeneities and random noise. Nearly all fMRI studies derive functional “activation” based on magnitudeonly voxel time courses. Here the entire complex or bivariate data are modeled rather than just the m...

introduction as functional magnetic resonance imaging (fmri) is too expensive and time consuming, its frequent implementation is difficult. the aim of this study is to evaluate repeatability of detecting visual cortex activity in fmri. materials and methods in this study, 15 normal volunteers (10 female, 5 male; mean age±sd: 24.7±3.8 years) attended. functional magnetic resonance images were ob...

This paper presents a voxel-based biomechanical model for muscle deformation using finite element method (FEM) and volume graphics. Hierarchical voxel meshes are reconstructed from filtered segmented muscle images followed by FEM simulation and volume rendering. Physiological muscle force is considered and linear elastic muscle models for both static and dynamic cases are simulated by FEM. Voxe...

In this paper a novel 3D model retrieval method that employs multi-level spherical moment analysis and relies on voxelization and spherical mapping of the 3D models is proposed. For a given polygon-soup 3D model, first a pose normalization step is done to align the model into a canonical coordinate frame so as to define the shape representation with respect to this orientation. Afterward we ras...