The diagnostic accuracy of single photon emission computed tomography (SPECT) is profoundly influenced by attenuation phenomenon. Soft tissue attenuation degrades cardiac SPECT image quality, thereby decreasing the possibility of the detection of the lesions. A variety of correction techniques based on different assumptions have been used to reduce the impact of attenuation. Several types of sy...

Samples of concrete contain various waste materials, such as iron particulates, steel balls of used ball bearings and slags from steel industry were assessed for their anti-radiation attenuation coefficient properties. The attenuation measurements were performed using gamma spectrometer of NaI (Tl) detector. The utilized radiation sources comprised 137Cs and ⁶⁰Co radioactive elements with photo...

Citrine is a transparent gemstone, yellow microcrystalline quartz variety. Natural citrine is very rare and will actually lose its color upon heating to more than 200°C, and the yellow color will occur again when the crystal is irradiated with Xor gamma-rays, indicating that attenuation parameters is important to enhancements by irradiation. In this work, the mass attenuation coefficients of ci...

PURPOSE The most common material for shielding is concrete, which can be made using various materials of different densities as aggregates. New techniques in radiotherapy, as IMRT and VMAT, require more monitor units and it is important to develop specifically designed shielding materials. METHODS Arraela S.L. has developed new concrete (CONTEK®-RFH2), which is made from an arid with a high p...

Half-value layer (HVL) is energy dependent on the photon, much as attenuation coefficient. Increasing penetrating of a photon stream causes an increase in substance's HVL. Before calculating HVL value, linear coefficient (μ) must be established. A review literature indicated that there presently no Monte Carlo-based sufficient tool for direct calculation value and computation suitable material ...

normal 0 false false false en-us x-none ar-sa aim: ct number (hu) and linear attenuation coefficient contain useful information which  can be determined during usual ct scanning for the prediction of breast cancerous cells existence based on hemoglobin concentration. methods: this study used breast phantom containing major and minor vessels with diameters of 10 and 5 mm, respectively. the major...

Background: In recent years, there has been an increased interest toward non-lead radiation shields consisting of small-sized filler particles doped into polymer matrices. In this paper, we study a new polyvinyl alcohol (PVA)/WO3 composite in the presence of high-energy gamma photons through simulation via the Monte Carlo N-Particle (MCNP) simulation code. Materia...

Background: This study aims to investigate radiation beam geometry of Cyberknife beam and change in dosimetric characteristics of six megavoltage (6MV) flattening filter free (FFF) beam after passing through high density cadmium free compensator alloy.Material and Methods: In this experimental study, changes in FFF beam dosimetric characteristics after passing through compensator alloy wa...

Background: Multiple beams are generally used with an increased possibility that the beam axis intersects the treatment table. Treatment tabletops are commonly made of carbon fiber due to its high mechanical strength and rigidity, low specific density, extremely light and low radiation beam attenuation properties. Purpose of this paper is investigated the dose changes in the buildup region and ...