background and aims. cone-beam computed tomography (cbct) is an imaging system which has many advantages over computed tomography (ct). in ct scan, hounsfield unit (hu) is proportional to the degree of x-ray attenuation by the tissue. in cbct, the degree of x-ray attenuation is shown by gray scale (voxel value). the aim of the present study was to investigate the relationship between gray scale...

introduction: cholesteatoma is traditionally diagnosed by otoscopic examination and treated by surgery. the necessity for imaging in an uncomplicated case is controversial. this study was planned to investigate the usefulness of a preoperative high-resolution computed tomography (hrct) scan in depicting the status of middle ear structures in the presence of cholesteatoma and also to compare the...

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...

for obtaining reservoir petrophysical properties, for example porosity, non-destructive methods such as x-ray computed tomography, ct, seems to be precise and accurate. porosity is deducted from the ct image with a single scan via different techniques, such as pore space detection by image segmentation techniques then correlation with porosity. more than one hundred samples with carbonate li...

objectives: bone quality and quantity assessment is one of the most important steps in implant treatment planning. different methods such as computed tomography (ct) and recently suggested cone beam computed tomography (cbct) with lower radiation dose and less time and cost are used for bone density assessment. this in vitro study aimed to compare the tissue density values in hounsfield units (...

primary pleuropulmonary synovial sarcomas are rare soft tissue malignancies; combined metastatic involvement of the heart is extremely rare. in this case report, a 17-year-old female presented with a history of chest pain. chest radiographs revealed a round mass in the left upper hemithorax, and computed tomography (ct) showed a well-defined heterogeneous enhancing mass abutting the pleura. a c...

two main forms of copd (chronic obstructive pulmonary disease) refer to a group of lung diseases that block airflow and cause a huge degree of human suffering. a new method for identifying and estimating the severity of copd from three-dimensional (3-d) pulmonary x-ray ct images would be helpful for evaluation of treatment effects and early diagnosing is presented in this paper. this method has...

for obtaining reservoir petrophysical properties, for example porosity, non-destructive methods such as x-ray computed tomography, ct, seems to be precise and accurate. porosity is deducted from the ct image with a single scan via different techniques, such as pore space detection by image segmentation techniques then correlation with porosity. more than one hundred samples with carbonate litho...

a 50-year-old male underwent a check-up for an insurance company. chest x-ray revealed a large ball-like lesion in the posterior mediastinum. the finding was confirmed by computed tomography (ct) scan (figure 1). the patient was referred to our center, where he had a successful mass removal surgery (figure 2). pathology identified the mass as neurinoma.