Angular dependence of Be(α, n)C was simulated in Monte-Carlo N-Particle transport 6.1.1 (MCNP) with TALYS Evaluated Nuclear Data Library (TENDL) 2012, 2014, and 2017 data to determine secondary neutron direction and energy for neutron imaging.
View Article and Find Full Text PDFJ Xray Sci Technol
July 2015
Background: While spectral CT using single photon counting detector has shown a number of advantages in diagnostic imaging, knowledge of the detector response function of an energy-resolved detector is needed to correct the signal bias and reconstruct the image more accurately.
Objective: The objective of this paper is to study the photo counting detector response function using laboratory sources, and investigate the signal bias correction method.
Methods: Our approach is to model the detector response function over the entire diagnostic energy range (20 keV
Local liquid velocity measurements in Trickle Bed Reactors (TBRs) are one of the essential components in its hydrodynamic studies. These measurements are used to effectively determine a reactor's operating condition. This study was conducted to validate a newly developed technique that combines Digital Industrial Radiography (DIR) with Particle Tracking Velocimetry (PTV) to measure the Local Liquid Velocity (V(LL)) inside TBRs.
View Article and Find Full Text PDFThe stationary grid commonly used with a digital x-ray detector causes a moiré interference pattern due to the inadequate sampling of the grid shadows by the detector pixels. There are limitations with the previous methods used to remove the moiré such as imperfect electromagnetic interference shielding and the loss of image information. A new method is proposed for removing the moiré pattern by integrating a carbon-interspaced high precision x-ray grid with high grid line uniformity with the detector for frequency matching.
View Article and Find Full Text PDFStereotactic radiosurgery (SRS) is a technique to delivering a high dose to a target region and a low dose to a critical organ by using only one or a few irradiations. Traditionally, SRS is performed using a Gamma knife with using 201 cobalt 60 sources or a linear accelerator with equally spaced noncoplanar arcs. Finding a specific condition that includes the target in the prescription dose while sparing the critical organ is tedious, because there are many combinations of positions and collimator sizes for each isocenter.
View Article and Find Full Text PDFTo investigate whether there are significant changes in regional brain metabolism in patients with Parkinson's disease before and after thalamotomy using proton magnetic resonance spectroscopy (1H MRS). Fifteen patients underwent 15 stereotactic thalamotomies for control of medically refractory parkinsonian tremor. Single-voxel 1H MRS was carried out on a 1.
View Article and Find Full Text PDFTo prove feasibility of proton chemical shift imaging ((1)H CSI) during stereotactic procedure, authors performed (1)H CSI in combination with a stereotactic headframe and selected targets according to local metabolic information, evaluated the pathologic results. The (1)H CSI directed stereotactic biopsy was performed in four patients. (1)H CSI and conventional Gd-enhancement stereotactic MRI were performed simultaneously after the fitting of a stereotactic headframe.
View Article and Find Full Text PDFObjective: To determine, using proton magnetic resonance spectroscopy (1H MRS) whether thalamotomy in patients with Parkinson's disease gives rise to significant changes in regional brain metabolism.
Materials And Methods: Fifteen patients each underwent stereotactic thalamotomy for the control of medically refractory parkinsonian tremor. Single-voxel 1H MRS was performed on a 1.