Introduction: Head scans are the most frequently performed computed tomography (CT) examinations worldwide. However, there is growing concern over the probability of increased cancer risks among the exposed populations. Diagnostic reference levels (DRLs) identify radiation dose that is not commensurate with clinical objectives. The aim of this study was to establish DR...

OBJECTIVES To determine the effective dose and CT dose index (CTDI) for a range of imaging protocols using the Sirona GALILEOS(®) Comfort CBCT scanner (Sirona Dental Systems GmbH, Bensheim, Germany). METHODS Calibrated optically stimulated luminescence dosemeters were placed at 26 sites in the head and neck of a modified RANDO(®) phantom (The Phantom Laboratory, Greenwich, NY). Effective dose...

CT has become the major source of population exposure to diagnostic X-rays. CT dose index (CTDI) and dose-length product (DLP) have been proposed as the appropriate dose quantities for the establishment of diagnostic reference levels for optimizing patient exposure. Dose measurements on 27 CT scanners in Northern Greece involving six routine CT examinations have been performed in order to compa...

BACKGROUND The technologic improvements in Multislice scanners include the increment in the X-ray beam width. Some new CT scanners are equipped with a 320 detector row which allows a longitudinal coverage of 160 mm and a total of 640 slices for a single rotation. When such parameters are used the length of the traditional pencil chamber (10 cm) is no more appropriate to measure the standard wei...

A common dose-saving technique used in modern CT devices is automatic tube current modulation (TCM), which was originally designed to also reduce the dose in paediatric CT patients. In order to be able to deduce detailed organ doses of paediatric models, dose conversion coefficients normalized to CTDI(vol) for an eight-week-old baby and seven- and eight-year-old children have been computed acco...

Introduction: Computed tomography (CT) has numerous applications in clinical procedures but its main problem is its high radiation dose to the patients compared to other imaging modalities using x-ray. CT delivers approximately high doses to the nearby tissues due to the scattering effect, fan beam (beam divergence) and limited collimator efficiency. The radiation dose from multi-slice scanners...

Introduction: An operational computed tomography (CT) scanner is a major source of human exposure to ionizing radiation. Exposure increases the risk of cancer and aplastic anaemia. All radiation exposures should be justified and optimized to meet the clinical objective. In order to avoid the administration of excessive radiation dose to patients, diagnostic reference l...

The new NCRP Report No. 147 includes methodology to determine x-ray protective shielding for CT scanner rooms. This methodology assumes fixed values of the scatter fraction per centimeter (kappa) for the peripheral axis of the head and body CT phantoms. An investigation was performed to determine kappa for different makes and models of CT scanner and examine the consequences of the differences ...

PURPOSE Combined ultrafast 90°+90° kV-MV-CBCT within single breath-hold of 15s has high clinical potential for accelerating imaging for lung cancer patients treated with deep inspiration breath-hold (DIBH). For clinical feasibility of kV-MV-CBCT, dose exposure has to be small compared to prescribed dose. In this study, kV-MV dose output is evaluated and compared to clinically-established kV-CBC...