Introduction: In patients with thyroid carcinoma, radiation absorbed doses of the thyroid and surrounding tissues is important to weigh risk and benefit considerations. In nuclear medicine, the accuracy of absorbed dose of internally distributed radionuclides is estimated by different methods such as MIRD and direct method using TLD. The aim of this study is using T...

An evaluation of two anthropomorphic breast phantoms, which have been designed for quality assurance and dose verification of radiotherapy treatment of breast cancer patients, is presented. These phantoms are identical in terms of their dimensions and shape, and composed of several layers of either Plastic Water or tissue-equivalent material. Both water- and tissue-equivalent phantoms include l...

Introduction: An accurate and fast radiation dose calculation is essential for successful radiation radiotherapy. The aim of this study was to implement a new graphic processing unit (GPU) based radiation therapy treatment planning for accurate and fast dose calculation in radiotherapy centers. Materials and Methods: A program was written for parallel runnin...

The characterization of the incident photon beam is usually divided into its dependence on collimator setting (head-scatter factor) and off-axis position (primary off-axis ratio). These parameters are normally measured "in air" with a build-up cap thick enough to generate full dose build-up at the depth of dose maximum. In order to prevent any influence from contaminating electrons, it has been...

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...

background:  radiochromic film is used for radiation dose measurement, xr-rv3 is used in fluoroscopy and ebt2 film in radiation therapy. the aim was to determine if the dosimetric properties of these two films are comparable in megavolt photon beams. materials and methods: comparison measurements included: calibration curves, heterogeneous phantom dose profiles, and nasopharynx dose distributio...

The aim of this study was to investigate the extent to which measurements made in an ADC (apparent diffusion coefficient) calibration phantom could be shown to correlate with accuracies of measurements made in normal liver. Ideally, a strong correlation might be used in the future in order to perform an assessment of scanner performance based entirely on the phantom. Several metrics of image qu...

Introduction: Magnetic resonance imaging (MRI) remains the primary standard for visualization of cartilage defects and overall assessment of cartilage morphology. As the initial stages of osteoarthritis (OA) arise from biochemical changes at the tissue level such as proteoglycan (PG) loss, the standard contrast mechanisms acquired as part of routine clinical MRI protocols are not typically sens...

introduction: in diagnostic and therapeutic procedures, dosimetric studies are performed on the dosimetric systems in order to comply the radiation safety standards. monte carlo methods are used due to the high complexity and cost of patient-specific phantom construction. the high complexity of the digitized phantoms greatly increases the time and computational task of the monte carlo calculati...