OBJECTIVE Aiming at contributing to the knowledge on doses in computed tomography (CT), this study has the objective of determining dosimetric quantities associated with pediatric abdominal CT scans, comparing the data with diagnostic reference levels (DRL). MATERIALS AND METHODS The study was developed with a Toshiba Asteion single-slice CT scanner and a GE BrightSpeed multi-slice CT unit in...

A comparison has been made of the air-kerma standards for low-energy x rays at the National Institute of Standards and Technology (NIST) and the Physikalisch-Technische Bundesanstalt (PTB). The comparison involved a series of measurements at the PTB and the NIST using the air-kerma standards and two NIST reference-class transfer ionization chamber standards. Results are presented for the refere...

where kD=1.602 10 Gy⋅g/MeV — energy conversion factor from MeV to Gy×g, (obtained from the known ratio: 1 MeV=1.602 10 J); Е – neutron energy, MeV; Ф(r,Е) dE – neutron flux in the point r on the energy interval dE, neutron/cm/s: ni – atomic density of the i-th nuclide of the medium, atom/cm; σij(E) –microscopic cross-section of reaction j at interaction of a neutron with energy Е on the i-th nu...

In recent times, ionizing radiation has been used around the world to screen persons for non-medical purposes, namely to detect bulk explosives or other contraband hidden on the body including materials not registered by metal detectors. In contrast to conventional transmission or projection imaging, backscatter and forward-scatter systems employ a "flying spot" of x rays and large-area detecto...

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 ...

Various radiation detectors including electronic personal emergency radiation detectors (PERDs), radiochromic film cards and thermoluminescent dosimeters (TLDs) were used to validate a subset of the radiological test requirements listed in the American National Standards Institute/The Institute of Electrical and Electronic Engineers (ANSI/IEEE) N42.49 standard. The subset of tests included the ...

In interventional cardiology, a wide variation in patient dose for the same type of procedure has been recognised by different studies. Variation is almost due to procedure complexity, equipment performance, procedure protocol and operator skill. The SENTINEL consortium has performed a survey in nine european centres collecting information on near 2000 procedures, and a new set of reference lev...

background: absolute dosimetry of external beam radiotherapy is carried out by the use of ionization chambers. these chambers must be calibrated at a standard dosimetry laboratory before any use in clinical dosimetry. the secondary standard dosimetry laboratory of iran (ssdl) has the duty of calibrating the ionization chambers used in radiotherapy centers in iran. materials and methods: the pre...

We present the behavioral changes and symmetrical enhancement on KERMA, mass stopping power projected range parameters against heavy-charged particles through Indium (In) Tantalum (Ta) incorporations for various zinc-tellurite glass groups such as TZI ZTT nuclear applications. SRIM PAGEX codes are utilized determination of investigated attenuation alpha proton particles. In KERMA calculations, ...

Doses due to external exposure of terrestrial biota are assessed using differential air kerma from radioactive sources in soil and energy-dependent 'absorbed dose-per-air kerma' conversion factors computed for spherical tissue-equivalent bodies. The presented approach allows computing average whole body absorbed dose for terrestrial organisms with body masses from 1 mg to 1,000 kg located at he...