9,208 research outputs found

    High spectral and spatial resolution X-ray transmission radiography and tomography using a Color X-ray Camera

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    High resolution X-ray radiography and computed tomography are excellent techniques for non-destructive characterization of an object under investigation at a spatial resolution in the micrometer range. However, as the image contrast depends on both chemical composition and material density, no chemical information is obtained from this data. Furthermore, lab-based measurements are affected by the polychromatic X-ray beam, which results in beam hardening effects. New types of X-ray detectors which provide spectral information on the measured X-ray beam can help to overcome these limitations. In this paper, an energy dispersive CCD detector with high spectral resolution is characterized for use in high resolution radiography and tomography, where a focus is put on the experimental conditions and requirements of both measurement techniques

    Reducing dose for digital cranial radiography : The increased source to the image-receptor distance approach

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    This investigation proposes that an increased source to the image-receptor distance (SID) technique can be used to optimize occipital frontal and lateral cranial radiographs acquired with direct digital radiography. Although cranial radiography is not performed on a routine basis, it should nonetheless be optimized to keep the dose to the patient as low as reasonably achievable, particularly because it can form part of the facial bone and sinus series. Dose measurements were acquired at various SIDs, and image quality was assessed using visual grading analysis. Statistically significant reductions in the effective dose between 19.2% and 23.9% were obtained when the SID was increased from the standard 100 to 150 cm (P ≤.05), and visual grading analysis scores indicate that image quality remained diagnostically acceptable for both projections. This investigation concludes that increasing the SID effectively optimizes occipital frontal and lateral skull radiographs. Radiology departments must be advised of the benefits of this technique with the goal of introducing an updated reference SID of 150 cm into clinical practice.Peer reviewe

    A LabVIEW® based generic CT scanner control software platform

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    UGCT, the Centre for X-ray tomography at Ghent University (Belgium) does research on X-ray tomography and its applications. This includes the development and construction of state-of-the-art CT scanners for scientific research. Because these scanners are built for very different purposes they differ considerably in their physical implementations. However, they all share common principle functionality. In this context a generic software platform was developed using LabVIEW (R) in order to provide the same interface and functionality on all scanners. This article describes the concept and features of this software, and its potential for tomography in a research setting. The core concept is to rigorously separate the abstract operation of a CT scanner from its actual physical configuration. This separation is achieved by implementing a sender-listener architecture. The advantages are that the resulting software platform is generic, scalable, highly efficient, easy to develop and to extend, and that it can be deployed on future scanners with minimal effort

    Optics and lasers: A compilation

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    A number of innovative devices and techniques in optics and related fields were presented. The following areas were covered: advances in laser and holography technology, articles on spectroscopy and general optics, new information in the area of photography

    A review of computer aided interpretation technology for the evaluation of radiographs of aluminum welds

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    Industrial radiography is a well established, reliable means of providing nondestructive structural integrity information. The majority of industrial radiographs are interpreted by trained human eyes using transmitted light and various visual aids. Hundreds of miles of radiographic information are evaluated, documented and archived annually. In many instances, there are serious considerations in terms of interpreter fatigue, subjectivity and limited archival space. Quite often it is difficult to quickly retrieve radiographic information for further analysis or investigation. Methods of improving the quality and efficiency of the radiographic process are being explored, developed and incorporated whenever feasible. High resolution cameras, digital image processing, and mass digital data storage offer interesting possibilities for improving the industrial radiographic process. A review is presented of computer aided radiographic interpretation technology in terms of how it could be used to enhance the radiographic interpretation process in evaluating radiographs of aluminum welds
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