This paper presents an algorithm for fast image synthesis inside deformed volumes. Given the node displacements of a mesh and a reference 3-D image dataset of a predeformed volume, the method first maps the image pixels that need to be synthesized from the deformed configuration to the nominal predeformed configuration, where the pixel intensities are obtained easily through interpolation in th...

Functional magnetic resonance imaging (fMRI) is widely used to pinpoint active brain areas. Changes in neuronal activity modulate the local blood oxygenation level, and the associated modulation of the magnetic field homogeneity can be detected with magnetic resonance imaging. Thus, the blood oxygenation level-dependent (BOLD) fMRI indirectly measures neuronal activity. Similar modulation of ma...

This paper reports the implementation of the SIMIND Monte Carlo code on an IBM SP2 distributed memory parallel computer. Basic aspects of running Monte Carlo particle transport calculations on parallel architectures are described. Our parallelization is based on equally partitioning photons among the processors and uses the Message Passing Interface (MPI) library for interprocessor communicatio...

PURPOSE The authors present an efficient method for generating anthropomorphic software breast phantoms with high spatial resolution. Employing the same region growing principles as in their previous algorithm for breast anatomy simulation, the present method has been optimized for computational complexity to allow for fast generation of the large number of phantoms required in virtual clinical...

Image processing is common in functional magnetic resonance imaging (fMRI) and functional connectivity magnetic resonance imaging (fcMRI). Such processing may have deleterious effects on statistical maps computed from the processed images. In this manuscript, we describe a mathematical framework to evaluate the effects of image processing on observed voxel means, covariances and correlations re...

Magnetic resonance fingerprinting (MRF) is a technique for quantitative estimation of spinrelaxation parameters from magnetic-resonance data. Most current MRF approaches assume that only one tissue is present in each voxel, which neglects the tissue’s microstructure, and may lead to artifacts in the recovered parameter maps at boundaries between tissues. In this work, we propose a multicompartm...

Changes in tissue mechanical properties, measured non-invasively by elastography methods, have been shown to be an important diagnostic tool, particularly for cancer. Tissue elasticity information, tracked over the course of therapy, may be an important prognostic indicator of tumor response to treatment. While many elastography techniques exist, this work reports on the use of a novel form of ...

This paper shows how to implement haptic rendering for a needle insertion problem with volume graphic model. The target is a spine biopsy simulator for tumor inspection by needle insertion. Simulated force is calculated from the relationship between voxel data and the orientation and position of the needle. At first, it is generated using PHANToM. The needle puncturing resistive force is calcul...

According to the International Atomic Energy Agency (IAEA), industrial radiography accounts for approximately half of all reported accidents for the nuclear related industry. Detailed information about these accidents has been published by the IAEA in its Safety Report Series, one of which describes the radiological accident which happened in 1999 in Yanango/Peru. Under unsettled circumstances ...

INTRODUCTION Accurate R2* measurements are critical for many quantitative imaging applications. R2* is estimated via mono-exponential fitting of signal decay within a series of gradient echo (GRE) images sampled at increasing TE. Root-sum-of-square (RSS) remains the most common approach to combine surface coil array images at each TE prior to the data fitting procedure. Rapid signal decay can r...