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X-ray coronary angiography has been a gold standard in the clinical diagnosis and interventional treatment of coronary arterial diseases for decades. In angiography, a sequence of images is obtained, a few of which are suitable for physician inspection. This paper proposes an automatic algorithm for the extraction of one or more frames from an angiogram sequence, which is most suitable for diagnosis and analysis by experts or processors. The algorithm consists of two stages: In the first stage, the background and illumination in the angiogram sequence are omitted. By analyzing the histogram of the sequence, a feature is attributed to each frame. These features, determining the visibility of the vessel tree, are clustered by a fuzzy c-means method. In the second stage, the cardiac phase for each frame is specified. Using the results of both stages, the best frames in an angiogram sequence are obtained. To evaluate the proposed method, it has been tested on angiogram sequences from several patients. The results demonstrate the accuracy of the method. The performance and speed of our method indicate its usefulness in clinical applications. [ABSTRACT FROM AUTHOR]

Photon counting detectors in Computed Tomography overcome several drawbacks of classical detectors used in Computed Tomography. Classical detectors measure X-rays by converting them into visible light during the initial absorption inside a pixel (individual scintillator cube which is separated mechanically from neighboring pixels) and then collecting the emitted visible light per pixel with a photo diode. High resolution imaging with scintillator-based detector experiences a limit due to the dose usage capabilities, low dose applications suffer from classical electronic noise and true material separation inside the scan object can only be performed, if the data acquisition was selected prior the scan examination (dual energy protocols). Photon counting detectors made of a semiconductor crystal which allows the detection of the incoming photons individually using a direct conversion process. The spatial resolution is defined electrically and only limited by the charge distribution inside the semiconductor. This enables sharper images without the dose penalty of interpixel gaps or post patient collimation. The contrast to noise ratio is increased by detecting each photon individually with respect to its energy. This additional energy information can be used during any diagnostic procedure to gain further detailed insights into the morphology and functionality of the scanned object. And finally, no classical noise is deteriorating the signal as the digitization of the signal is done during the initial detection. Photon counting detectors lead the way to higher contrasts, higher resolution, and lower doses which may help elevating the potential of computed tomography. Upcoming studies will evaluate the true potential of this technology and point to the variety of clinical fields which may profit from this imaging modality to make all humans lives healthier. [ABSTRACT FROM AUTHOR]

Synchrotron X-ray imaging systems with fluorescence techniques were developed for biomedical research at the Brazilian Synchrotron Laboratory. Two different X-ray fluorescence systems were implemented to analyze human prostate samples with and without disorders. [ABSTRACT FROM PUBLISHER]