introduction: computed tomography (ct) and cone-beam ct (cbct) are valuable diagnostic aids for many clinical applications. this study was designed to compare the gray scale value (gsv) and hounsfield unit (hu) of selected dental materials and various hard tissues using ct or cbct. methods and materials: three samples of all test materials including amalgam (am), composite resin (cr), glass ion...

Many different techniques and researches on reducing the radiation dose for computed tomography (CT) examinations have been reported and developed in recent 30 years. However, most those technologies are not practical enough to enable them to be directly and easily implemented in clinic real applications because there is no directly relationship between those techniques and the actual CT scanni...

conclusions ultrasound is recommended as the first choice when fb is located within the superficial soft tissues with no bone around it. in case of penetration of fb into deeper tissues or beneath bone, ct or cbct are recommended. otherwise, considering lower dose, cbct is preferred over ct. we can use mri if the fb is not ferromagnetic. however, ct is the first choice in emergency situations b...

INTRODUCTION The aim of this study was to establish institutional diagnostic reference levels (DRLs) by summarising doses collected across the five computed tomography (CT) system in our institution. METHODS CT dose data of 15940 patients were collected retrospectively from May 2015 to October 2015 in five institutional scanners. The mean, 75th percentile and 90th percentile of the dose sprea...

We performed a prospective study in patients with chemotherapy induced febrile neutropenia to investigate the diagnostic value of low-dose computed tomography compared to standard chest radiography. The aim was to compare both modalities for detection of pulmonary infections and to explore performance of low-dose computed tomography for early detection of invasive fungal disease. The low-dose c...

Background:  This study presents patient specific and organ dose estimation in computed tomography (CT) imaging of thorax directly from patient CT image using Monte Carlo simulation.  Patient's CT image is considered as the patient specific phantom and the best representative of patient physical index in order to calculate specific organ dose. Materials and Methods: EGSnrc /BEAMnr...

Diagnostic reference levels (DRLs) are an important optimisation tool, which aid in identifying abnormally high dose levels. These are currently not available in Saudi Arabia, and this research aims to remedy this. CT dose data (DLP and CTDIvol) were collected for a minimum number of 10 adult patients of average size (60-80 kg) presenting for a range of CT examinations from public hospitals in ...

Introduction: The study aimed to assess absorbed and effective doses in organs through computed tomography (CT) examinations using automatic exposure control (AEC) and fixed tube current (FTC) techniques. Material and Methods: Scanning parameters were obtained for routine adult CT examinations and used to estimate the organ absorbed and effec...

Emerging concerns regarding the hazard from medical radiation including CT examinations has been suggested. The purpose of this study was to observe the longitudinal changes of CT radiation doses of various CT protocols and to estimate the long-term efforts of supervising radiologists to reduce medical radiation. Radiation dose data from 11 representative CT protocols were collected from 12 hos...