One can divide the existing ionospheric methods for SBAS in two categories: tomography and methods relying on the thin shell model. At first sight, tomography appears to be the right choice. Tomography reconstructs the three dimensional density of the ionosphere from the available measurements. However, there are several drawbacks to tomography: the system of equations to be solved is often und...

PURPOSE To develop a projection quality-driven tube current modulation method in cone-beam computed tomography for image-guided radiotherapy based on the prior attenuation information obtained by the planning computed tomography and then evaluate its effect on a reduction in the imaging dose. MATERIALS AND METHODS The QCKV-1 phantom with different thicknesses (0-400 mm) of solid water upon it...

Electron tomography is a well-established technique for three-dimensional structure determination of (almost) amorphous specimens in life sciences applications. With the recent advances in nanotechnology and the semiconductor industry, there is also an increasing need for high-resolution three-dimensional (3D) structural information in physical sciences. In this article, we evaluate the capabil...

Conventional radiographs used for the management of endodontic problems yield limited information because of the two-dimensional nature of images produced, geometric distortion and anatomical noise. These factors often act in combination. This review paper assesses the limitations of periapical radiographs and seeks to clarify three-dimensional imaging techniques that have been suggested as adj...

Recently, techniques for the acquisition of three-dimensional tomographic and four-dimensional time-resolved data sets have emerged, allowing for the analysis of mm volumes of material with nm-scale resolution. The ability to merge multi-modal data sets acquired via multiple techniques for the quantitative analysis of structure, chemistry and phase information is still a significant challenge. ...

Organismal colour can be created by selective absorption of light by pigments or light scattering by photonic nanostructures. Photonic nanostructures may vary in refractive index over one, two or three dimensions and may be periodic over large spatial scales or amorphous with short-range order. Theoretical optical analysis of three-dimensional amorphous nanostructures has been challenging becau...

studying crustal and upper mantel structures has been limited in the iranian plateau and there has been little work done in this field. in this paper we have a primary motive to map pn and sn velocities beneath most of the iranian plateau in order to test 3-d mantle models and to develop and test a method to produce pn and sn travel time correction surfaces that are the 3-d analogue of travel t...

Abbreviations 2D, 3D 2-dimensional, 3-dimensional CZT cadmium zinc telluride EKG electric signal from the heart FBP filtered backprojection FOV field-of-view GE General Electric Ge(Li) germanium detector doped with lithium MLEM maximum likelihood expectation maximization NaI(Tl) sodium iodine doped with thallium NM nuclear medicine OSEM ordered subset expectation maximization PET positron emiss...

Diffuse optical correlation methods were adapted for three-dimensional (3D) tomography of cerebral blood flow (CBF) in small animal models. The image reconstruction was optimized using a noise model for diffuse correlation tomography which enabled better data selection and regularization. The tomographic approach was demonstrated with simulated data and during in-vivo cortical spreading depress...

Introduction: Cone beam computed tomography (CBCT) was introduced and became more common based on its low cost, fast image procedure rate and low radiation dose compared to CT. This imaging modality improved diagnostic and treatment-planning procedures by providing three-dimensional information with greatly reduced level of radiation dose compared to 2D dental imaging modalitie...