This study describes the importance of attenuator scatter in the construction of compensators. The attenuator used in this study was Lipowitz metal, commonly referred to as cerrobend. Linear attenuation coefficients of cerrobend were measured in air for different thickness of cerrobend sheets and different field sizes for a 6-MV photon beam. The magnitude of the dose contribution from photons s...

We propose a new method to reduce the effects of non-linearities such as beam hardening in Computed Tomography (CT) images. Due to the polychromatic characteristics of X-ray sources the ratio of attenuated and incoming intensity is not exactly exponential with the material thickness. Within CT images this leads to artifacts like cupping, streaks and blurring. Especially in multi-material object...

A fiber detector concept is suggested allowing to registrate particles within less than 100 nsec with a space point precision of about 100 μm at low occuppancy. The fibers should be radiation hard for 1 Mrad/year. Corresponding prototypes have been build and tested at a 3 GeV electron beam at DESY. Preliminary results of these tests indicate that the design goal for the detector is reached.

BACKGROUND AND AIMS At present, cone beam computed tomography (CBCT) has become a substitute for computed tomography (CT) in dental procedures. The metallic materials used in dentistry can produce artifacts due to the beam hard-ening phenomenon. These artifacts decrease the quality of images. In the present study, the number of artifacts as a result of beam hardening in the images of dental imp...

We present in situ transmission electron microscope tensile tests on focused ion beam fabricated single and multiple slip oriented Cu tensile samples with thicknesses in the range of 100-200 nm. Both crystal orientations fail by localized shear. While failure occurs after a few percent plastic strain and limited hardening in the single slip case, the multiple slip samples exhibit extended homog...

The advent of the use of digital area detectors in Volumetric Computed Tomography (VCT) systems has brought with it the challenges of achieving image quality comparable to that provided by earlier planar industrial CT systems equipped with highly collimated and efficient linear detector arrays. Particularly for imaging with higher voltage x-ray sources up to 450kVp, among the most distinct imag...

The objective of this article is to review the mechanisms, advantages and disadvantages of dual energy computed tomography (DECT) over conventional tomography (CT) in musculoskeletal imaging as DECT provides additional information about tissue composition and artifact reduction. This provides clinical utility in detection of urate crystals, bone marrow edema, reduction of beam hardening metalli...

This article deals with the enhancement of accuracy in CT by just-in-time correction of artefacts (beam hardening, scattered radiation) caused by the interaction of X-rays with matter. The so called EAR method needs for simulation a registration of the object. Therefore the article presents two different registration concepts.