The sum of all attenuation data acquired in one view of parallel-beam projections is a view angle independent constant. This fact is known as a data consistency condition on the two-dimensional Radon transforms. It plays an important role in tomographic image reconstruction and artifact correction. In this paper, a novel fan-beam data consistency condition (FDCC) is derived and presented. Using...

Introduction: The aim of this study was to investigate the initial electron beam parameters for Monte Carlo model of 6MV photon beam produced by Siemens Oncor® linear accelerator.   Materials and Methods: In this study, the EGSnrc Monte Carlo user codes BEAMnrc and DOSXYZnrc were used. The beamnrc code were used for modelling of a 6 MV photon beam produced by...

Objective: The aim of the present study is to simulate 6 MV and 18 MV photon beam energies of a Siemens Primus Plus medical linear accelerator (Linac) and to verify the simulation by comparing the results with the measured data.Methods: The main components of the head of Siemens Primus Plus linac were simulated using MCNPX Monte Carlo (MC) code. To verify the results, experimental data of perce...

INTRODUCTION Recently, fabrication of nanodots structure of various materials has attracted intense scientific interests because of their great potentials for wide technological applications. Metal nanoscale dots that exhibit unique properties based on their nano size effects are expected to be the building blocks of new functional nanodevices, such as catalysis, environmental remediation, DNA ...

The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) can measure the elevations of Earth’s surface using a sampling strategy with unprecedented spatial detail. In daytime mountainous areas where signal–noise ratio (SNR) weak beam data is very low, current algorithms do not always perform well on extracting signal photons from (i.e., many were missed). This paper proposes an effective algor...

We demonstrate one-to-one pixel–matching of phase–conjugate digital volume holographic data storage, with data pages as large as a megapel (1024 × 1024 pixels). A self–pumped phase–conjugate mirror in BaTiO3 is used to provide a phase–conjugate reference beam, which reconstructs the data–bearing object beam from a LiNbO3:Fe crystal using the 90◦ geometry. The systems tradeoffs of phase–conjugat...

This paper presents analytical fan-beam and cone-beam reconstruction algorithms that compensate for uniform attenuation in single photon emission computed tomography. First, a fan-beam algorithm is developed by obtaining a relationship between the two-dimensional (2D) Fourier transform of parallel-beam projections and fan-beam projections. Using this relationship, 2D Fourier transforms of equiv...