Respiratory motion can cause artifacts in myocardial SPECT. We incorporate respiratory mechanics into the current 4D MCAT and into the next generation spline-based MCAT phantoms. In order to simulate respiratory motion in the current MCAT phantom, the geometric solids for the diaphragm, heart, ribs, and lungs were altered through manipulation of parameters defining them. Affine transformations ...

Analytical phantoms are used to generate projection data for testing reconstruction accuracy in computed axial tomography. A circular source locus (equivalent to rotating specimen with a fixed source) provides insufficient data for ‘exact’ reconstruction in cone-beam transmission tomography, thus phantom data are useful for studying the consequent errors and also for investigating alternative s...

BACKGROUND Computational fluid dynamics (CFD) simulations using medical-image-based anatomical vascular geometry are now gaining clinical relevance. This study aimed at validating the CFD methodology for studying cerebral aneurysms by using particle image velocimetry (PIV) measurements, with a focus on the effects of small geometric variations in aneurysm models on the flow dynamics obtained wi...

  Introduction: Attenuation correction is a useful process for improving myocardial perfusion SPECT and is dependent on activity and distribution of attenuation coefficients in the body (attenuation map). Attenuation artifacts are a common problem in myocardial perfusion SPECT. The aim of this study was to compare the effect of attenuation correction using different a...

introduction based on task group no. 43 (tg-43u1) recommendations, water phantom is proposed as a reference phantom for the dosimetry of brachytherapy sources. the experimental determination of tg-43 parameters is usually performed in water-equivalent solid phantoms. the purpose of this study was to determine the conversion factors for equalizing solid phantoms to water. materials and methods t...

Dose distribution inside the human body due to external photon exposure was measured. Radiation detectors were imaging plate (IP) sheets and thermoluminescent dosimeters (TLD). Each IP sheet was installed between horizontally sliced pieces of a rando-phantom. TLDs were also installed inside/around the position of a target organ of the phantom. The rando-phantom was exposed to a photon beam of C...

Limb amputation results in plasticity of connections between the brain and muscles, with the cortical motor representation of the missing limb seemingly shrinking, to the presumed benefit of remaining body parts that have cortical representations adjacent to the now-missing limb. Surprisingly, the corresponding perceptual representation does not suffer a similar fate but instead persists as a p...

Background: Some tissues in human body are radiobiologically different from water and these inhomogeneity must be considered in dose calculation in order to achieve an accurate dose delivery. Dose verification in complex radiation therapy techniques, such as intensity‐modulated radiation therapy (IMRT) calls for volumetric, tissue equivalent and energy independent dosimeter. The purpose of this...