Introduction: This study, evaluate pediatric digital radiography. Due to the high rates of this test and the high sensitivity of children to ionizing radiation in comparison with adults, it is attempted to achieve near optimal conditions by reducing the dose and maintaining the image quality. The object of the study is to change the irradiation parameters such as kV and mA and ...

Introduction: One of the most valuable goals of phantoms, replacing with human goals in the field of research and quality control of diagnostic X-ray systems. There are various algorithms and methods for obtaining Homogeneity and CT number linearity for CT scan device. One of the most famous of these methods, the method is to use a uniform and homogeneous environment to comput...

PURPOSE It is estimated that every year, 1 × 10(6) women are diagnosed with breast cancer, and more than 410,000 die annually worldwide. Digital Image Elasto Tomography (DIET) is a new noninvasive breast cancer screening modality that induces mechanical vibrations in the breast and images its surface motion with digital cameras to detect changes in stiffness. This research develops a new automa...

The use of electronic portal imaging devices (EPIDs) is a promising method for the dosimetric verification of external beam, megavoltage radiation therapy-both pretreatment and in vivo. In this study, a previously developed EPID back-projection algorithm was modified for IMRT techniques and applied to an amorphous silicon EPID. By using this back-projection algorithm, two-dimensional dose distr...

BACKGROUND To analyse limits and capabilities in dose calculation of collapsed-cone-convolution (CCC) algorithm implemented in helical tomotherapy (HT) treatment planning system for thorax lesions. METHODS The agreement between measured and calculated dose was verified both in homogeneous (Cheese Phantom) and in a custom-made inhomogeneous phantom. The inhomogeneous phantom was employed to mi...

Light-tissue interaction is common in clinical treatments and medical research, therefore investigation of light path in irradiated tissues is of high importance. In this research, reflected light intensity measurements from different homogeneous phantoms, combined with numerical simulations, have been used for the investigation of phantoms absorption properties. Our results suggest a good fitt...

introduction: in this paper, by complete definition of human eye containing the various parts and their materials, the difference between this model and a homogeneous water phantom are compared for two ophthalmic plaques using 125i and 103pd. material and methods: the simulation of the two phantoms were performed in the mcnp-4c code and by using the geometry of a three-dimensional eye, differen...

Background: To enhance the dose to tumor, the use of high atomic number elements has been proposed.Objective: The aim of this study is to investigate the effect of gold nanoparticle distribution on dose enhancement in tumor when the tumor is irradiated by typical monoenergetic X-ray beams by considering homogeneous and inhomogeneous distributions of gold nanoparticles (GNPs) in the tumor.Method...

Introduction: To enhance the dose to tumor, the use of high atomic number elements has been proposed. Objective: The aim of this study is to investigate the effect of gold nanoparticle distribution on dose enhancement in tumor when the tumor is irradiated by typical monoenergetic X-ray beams by considering homogeneous and inhomogeneous distributions of gold nanoparticles (GNPs)...

Introduction. Conventional gradient calibration procedures do not exclude significant bias in the diffusion-weighted (DW) signal during MR experiments. The error, arising from imperfections in the DW gradients, varies among the different gradient directions and exhibits different extent of offsets. We propose a calibration method for DW imaging using a homogeneous water phantom, presuming that ...