Abstract Background To quantify the amount of scattered radiation reaching breasts during x-ray and CT investigations head in order to find appropriate justification for an intended change practice involving torso shielding. Results Scattered from reached both procedures. The range mean dose were (CR 1.02–3.61/1.94 ± 0.63 mGy) (CT 2.20–8.50/3.74 2.28 mGy). Both had enormous difference CR (72.3%...

In this work, a novel three-dimensional superposition algorithm for photon dose calculation is presented. The dose calculation is performed as a superposition of pencil beams, which are modified based on tissue electron densities. The pencil beams have been derived from Monte Carlo simulations, and are separated into lateral and depth-directed components. The lateral component is modeled using ...

The use of a multileaf collimator in the dynamic mode to perform intensity modulated radiotherapy became a reality at our institution in 1995. Unlike treatment with static fields using a multileaf collimator, there are significant dosimetric issues which must be assessed before dynamic therapy can be implemented. We have performed a series of calculations and measurements to quantify head scatt...

The purpose of this study was to develop and evaluate the hybrid scatter correction algorithm (HSC) for CT imaging. Therefore, two established ways to perform scatter correction, i.e. physical scatter correction based on Monte Carlo simulations and a convolution-based scatter correction algorithm, were combined in order to perform an object-dependent, fast and accurate scatter correction. Based...

The Camera Augmented Mobile C-arm (CamC) system that extends a regular mobile C-arm by a video camera provides an X-ray and video image overlay. Thanks to the mirror construction and one time calibration of the device, the acquired X-ray images are co-registered with the video images without any calibration or registration during the intervention. It is very important to quantify and qualify th...

We compared light-induced fluorescence (LIF) to nominal injected drug dose for predicting the depth of necrosis response to photodynamic therapy (PDT) in a murine tumor model. Mice were implanted with radiation-induced fibrosarcoma (RIF) and were injected with 0, 5, or 10 mg/kg Photofrin. 630-nm light (30 J/cm(2), 75 mW/cm(2)) was delivered to the tumor after 24 hours. Fluorescence emission (la...

OBJECTIVES Dosimetric control of staff exposure during interventional procedures under fluoroscopy is of high relevance. In this paper, a novel ray casting approximation of radiation transport is presented and the potential and limitation vs. a full Monte Carlo transport and dose measurements are discussed. METHOD The x-ray source of a Siemens Axiom Artix C-arm is modeled by a virtual source ...

HYPOTHESIS Processes of scattering and attenuation were investigated to determine the consequence on dose distributions by having a cochlear implant in the field of therapeutic radiation. BACKGROUND Radiation oncology medical accelerator beams of 6- and 18-MV x-ray energy were used. Five cochlear implants were investigated. METHODS Each implant model was individually studied using computer ...