the presence of anatomic variations of paranasal sinuses must be noted in order to attain a full understanding and accurate diagnosis of chronic sinusitis. the frequency of anatomic variations in chronic sinusitis is different in various studies. the purpose of this study is to assess the frequency of anatomic variations in chronic sinusitis patients admitted to otolaryngology ward of shahid sa...

introduction in ct imaging, metallic implants inside the tissues cause metal artifact that reduce the quality of image for diagnosis. in order to reduce the effect of this artifact, a new method with more appropriate results has been presented in this research work. materials and methods the presented method comprised of following steps: a) image enhancement and metal areas extraction, b) sinog...

ct image quality has been affected by many factors such as kvp, ma, exposure time, alogorithm and section thickness. gantry tilt has the main role in visualization of the temporal bone anatomic structures. in this study, we tried to optimize these factors to determine the best gantry tilt. this study was performed on the human skull phantom and then extended to 15 patients. the phantom was made...

background: to reduce uncertainties of patient positioning, the computerized tomography (ct) images acquired at the treatment planning time can be compared with those images obtained during radiation dose delivery. this can be followed during dose delivery procedure as image guided radiotherapy (igrt) to verify the prescribed radiation dose delivery to the target as well as to monitor radiation...

background: this study set out to evaluate the utility of cerebrovascular virtual non-contrast (vnc) scans. materials and methods: conventional non-contrast (cnc) and dual-energy computed tomography angiography (de-cta) head scans were conducted on 100 subjects, of which 46 were normal, 15 had parenchymal hematomas of the brain, 13 had ischemic infarction, 22 had tumors, and 4 had calcified les...

conclusions recent treatment, in addition to age, gender and daylight duration were proved as strong independent determinants on bat development and the level of metabolic activity at [18 f] dg pet/ct and should be considered as an important confounding factor in future researches. results one-hundred eighteen studies were recognized to demonstrate foci of fdg bat uptake (3.1%, mean age: 22.7 y...