conclusions modern cts with the innovative technology of a built-in tin filter allow for significant reduction of radiation exposure in patients with suspected urolithiasis by optimizing the x - ray spectrum with image quality as high as in standard ct devices results ct examinations of a total of 143 patients were assessed. dlp of force was 56% and 55% lower in comparison to as+ and flash, (74...

Computed Tomography (CT) images taken in cancer treatments are important treatment portal design and planning. The dose received by the patient CT scans not considered planning calculation becomes calculating limit doses of critical organs with threshold. In this study, change some organs, namely heart, liver, kidneys, according to height was investigated NCICT code using Monte Carlo technique....

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...

Background: As the volumetric modulated arc therapy (VMAT) becoming a main role of treatment ways, the effect of couch top becomes more significant. It is imperative to re-evaluate the couches that previously may have been considered of no importance during early treatment techniques. The impact of couch top on radiation delivery was explored and the couch model was tested with the aim of reduc...

Introduction: Recently, the use of nanoparticles has increased for many purpose in medicine. One of these is using the nano particles in shields structure to protect sensitive organs such as breast which placed inside the field of chest CT scan and receives high dose. The aim of this study was the use of nano Bi2O3 to making shield for protection breast in chest CT examination ...

In a patient with features indicating the presence of pseudotumor cerebri, a negative cranial CT-scan is not adequate to rule out less benign pathology and an MRI of brain should be performed. In this study, a 10-year old boy with daily headaches for one month and diplopia for one week was found to have a partial abducens palsy and bilateral papilledema; otherwise, his examination was normal. A...

PURPOSE Lung cancer screening with CT has been recently recommended for decreasing lung cancer mortality. The radiation dose of CT, however, must be kept as low as reasonably achievable for reducing potential stochastic risks from ionizing radiation. The purpose of this study was to calculate individual patients' lung doses and to estimate cancer risks in low-dose CT (LDCT) in comparison with a...

Background: Palliative whole brain radiotherapy (WBRT) has been the standard treatment for brain metastases. Ionizing radiation is known to be one of the most potent cataractogenic agents. We aimed to evaluate two different radiotherapy techniques with respect to the doses received by the organs at risk (OAR) in patients with brain metastasis who undergone WBRT. Materials and Methods: Ten conse...

Background: This study evaluates dosimetric and spatial variations in inter–fraction applicator positioning in high dose rate (HDR) brachytherapy. Materials and Methods: This study includes 25 retrospective patients of carcinoma of the cervix. Each patient received 5 fractions of HDR intracavitary brachytherapy. High Risk-Clinical Target Volume (HR-CTV) were drawn on CT images. First impl...