introduction in computed tomography (ct) technology, an optimal radiation dose can be achieved via changing radiation parameters such as ma, pitch factor, rotation time and tube voltage (kvp) for diagnostic images. materials and methods in this study, the brain, abdomen, and thorax scaning was performed using toshiba 16-slice scannerand standard aapm and ctdi phantoms. aapm phantom was used for...

introduction wedge modifiers are commonly applied in external beam radiotherapy to change the dose distribution corresponding to the body contour and to obtain a uniform dose distribution within the target volume. since the radiation dose delivered to the target must be within ±5% of the prescribed dose, accurate dose calculation by a treatment planning system (tps) is important. the objective ...

the present paper has determined the radioactivity concentrations, which are due to natural occurrence of radionuclides along with heavy metal concentration in water, sediment, and fish from 2 reservoirs in ghana. heavy metal concentrations in all samples were generally within the who safe limits with the average activity concentrations of 238u, 232th, and 40k in water being respectively 0.42±0...

large quantities of radiopharmaceuticals prescribed for treatment and diagnosis are excreted through kidney. therefore, radiation unwanted dose is created in kidney. as a result, exact calculation of prescribed radiopharmaceuticals amount is important. monte carlo method is used for simulation of radiation transport in body due to random nature of radiation. in this research, for the first time...

large quantities of radiopharmaceuticals prescribed for treatment and diagnosis are excreted through kidney. therefore, radiation unwanted dose is created in kidney. as a result, exact calculation of prescribed radiopharmaceuticals amount is important. monte carlo method is used for simulation of radiation transport in body due to random nature of radiation. in this research, for the first time...

background: the number of interventional cardiology (ic) procedures has increased rapidly. coronary angiography (ca) and percutaneous transluminal coronary angioplasty (ptca) are now widely performed as a matter of routine, and they are considered safe procedures for experienced cardiologists. however, it is also known that these procedures are associated with high radiation doses due to long f...

background: radiation-sensitive polymer gels are among the most promising three-dimensional dose verification tools and tissue-like developed to date. among the special features of this type of dosimeters, is be doped with other elements or chemicals which made them appropriate for investigating of dose enhancement with contrast agents, by high atomic number. material and methods: in this study...

background: the anatomic position and proven radiosensitivity of the thyroid make it an organ of concern in dental x-ray examinations. a national radiation protection department (nrpd)-sponsored pilot study carried out in the dental radiology department of rums., to assess if the radiation dose in panoramic radiographies could be reduced without significant impairment of the subjective image qu...

abstract   the mutagenic and immunosuppressory effects of cyclophosphamide (cyp) are still the primary limitation to wider application for treating a variety of human malignancies. on the one hand, cyp treatment predisposes transplant recipients and cancer patients to risk of bacterial, fungal, and viral infections, in the other word the, lipopolysaccharide (lps), an endotoxin found in cell wal...

More and more modern data management systems are defined using ontologies. Ontologies provide the basis for structuring data of a given application domain, possibly coming from multiple sources, in order to facilitate their interrogation. In many application domains, comprehensive ontologies resulting from collaborative initiatives are made available. Such well-established ontologies are often ...