background: use of contrast agents (cas) during ct simulation for treatment planing system leads to changes in  electron density. in this study we aimed to investigate the effect on  calculated dose of various concentrations of cas on treatment planing systems in different dose calculation algorithms. materials and methods: contrast agent (0.769 mg/ml iopromid) - water mixtures at concentration...

background: jaw bone quality plays an essential role in treatment planning and prognosis of dental implants. regarding several available methods for bone density measurements, they are not routinely used before implant surgery due to hard accessibility. objective: an in vitro investigation of correlation between average gray scale in direct digital radiographs and hounsfield units in ct-scan pr...

Background: Jaw bone quality plays an essential role in treatment planning and prognosis of dental implants. Regarding several available methods for bone density measurements, they are not routinely used before implant surgery due to hard accessibility.Objective: An in vitro investigation of correlation between average gray scale in direct digital radiographs and Hounsfield units in CT-Scan pro...

BACKGROUND AND PURPOSE Thrombolytic efficacy of intraventricular rtPA for acute intraventricular hemorrhage may depend on hematoma composition. We assessed whether hematoma Hounsfield unit quantification informs intraventricular hemorrhage clearance after intraventricular rtPA. MATERIALS AND METHODS Serial NCCT was performed on 52 patients who received intraventricular rtPA as part of the Clo...

OBJECTIVE  To compare the non-contrast computed tomography (NCCT) scan-based parameters of ureteric stones affecting the outcome of extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS We retrospectively evaluated the pre-procedure NCCT of 74 patients who had ESWL for solitary ureteric calculi of 5-20 mm in diameter. We assessed the age, sex, basal metabolic index (BMI), latera...

BACKGROUND Jaw bone quality plays an essential role in treatment planning and prognosis of dental implants. Regarding several available methods for bone density measurements, they are not routinely used before implant surgery due to hard accessibility. OBJECTIVE An in vitro investigation of correlation between average gray scale in direct digital radiographs and Hounsfield units in CT-Scan pr...

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...