Abstract:
The disclosure contains a method of quantifying and/or evaluating metal ions in a dentifrice, wherein the method comprises subjecting the dentifrice to X-ray absorption spectroscopy (XAS), and wherein the XAS is used to measure and/or evaluate the metal ions in the dentifrice. Also disclosed are methods of selecting and screening for dentifrices based upon the evaluation and quantification of their metal ion content.
Abstract:
There is provided a method and corresponding system and apparatus for image reconstruction based on image data from a photon-counting multi-bin x-ray detector. The method comprises determining (S1) parameter(s) of a given functional form of the relationship between comparator settings expressed in voltage in the read-out chain of the x-ray detector and the corresponding energy threshold values expressed in energy based on a fitting procedure between a first set of data representative of a measured pulse height spectrum and a second set of data representative of a reference pulse height spectrum. The method also comprises performing (S2) image reconstruction based on the image data and the determined parameter(s). In this way, efficient high-quality image reconstruction can be achieved.
Abstract:
L'invention concerne une méthode d'estimation du numéro atomique effectif d'un matériau à partir d'un spectre de transmission dudit matériau. On calcule dans un premier temps (230) une fonction de vraisemblance du numéro atomique effectif et de l'épaisseur du matériau à partir du spectre de transmission ainsi que des spectres de calibration, obtenus, dans une phase de calibration préalable, pour une pluralité d'échantillons de matériaux de calibration de nombres atomiques effectifs connus et d'épaisseurs connues. On estime ensuite (240) le numéro atomique effectif (I) du matériau à partir de valeurs de la fonction de vraisemblance.
Abstract:
An embodiment in accordance with the present invention provides a new SR compensation (SRC) method, using a more efficient conjugate gradient method. In this method, the first and second derivatives are directly calculated analytically. The proposed SRC uses a sinogram restoration approach, integrates the SRF as a part of a forward imaging model, and compensates for the effect of the SR by maximizing the Poisson log-likelihood of measurements. The algorithm can be evaluated using as a simulated fan-beam x-ray CT scanner.
Abstract:
본 발명은 이중 에너지 X-선 흡광분석을 이용한 X-선 영상장치에 관한 것으로서, 더욱 상세하게는 X-선원으로부터 발생된 광대역의 에너지 스펙트럼을 갖는 X-선을 병렬로 연결된 한 쌍의 필터를 통과시켜 저준위 에너지 스펙트럼을 갖는 저준위 X-선 빔과, 고준위 에너지 스펙트럼을 갖는 고준위 X-선 빔으로 각각 분리하여 피사체에 주사하고, 이렇게 분리되어 피사체를 통과한 저준위 X-선 빔과 고준위 X-선 빔을 병렬구조로 구비되는 한 쌍의 영상 검출기를 통해 각각 독립적으로 검출함으로써 대조도가 높은 양질의 X-선 영상을 획득하여 피사체의 구성 성분에 대한 식별 능력을 향상시킬 수 있는 이중 에너지 X-선 흡광분석을 이용한 X-선 영상장치에 관한 것이다. 본 발명에 따른 이중 에너지 X-선 흡광분석을 이용한 X-선 영상장치는, X-선 빔을 방출하는 X-선원과; 상기 X-선원에서 방출되는 X-선 빔이 출사되는 부분에 구비되되, 상기 X-선원으로부터 방출되는 X-선 빔에서 저준위 에너지 스펙트럼을 갖는 저준위 X-선 빔만을 선별적으로 통과시키는 제1필터와, 상기 X-선원으로부터 방출되는 X-선 빔에서 고준위 에너지 스펙트럼을 갖는 고준위 X-선 빔만을 선별적으로 통과시키는 제2필터가 병렬로 연결되어 구성되는 X-선 필터와; 상기 X-선 필터의 후방에 구비되어, 상기 X-선 필터를 통과한 저준위 X-선 빔과 고준위 X-선 빔의 형상 및 진행방향을 결정하는 콜리메이터; 및 상기 콜리메이터의 후방에 소정 거리 이격되어 구비되어, 상기 저준위 X-선 빔과 고준위 X-선 빔을 각각 검출할 수 있도록 병렬로 구비되는 한 쌍의 영상 검출기;를 포함하여 구성되는 것을 특징으로 한다.
Abstract:
The application discloses systems and methods for determining an atomic number of a material being scanned by generating a predetermined number of transmission data samples, determining a variance of the transmission data samples, and determining the atomic number of the material being scanned by comparing the variance or a derivative of the variance of the transmission data samples to one or more predetermined variances. The application also discloses systems and methods for determining an atomic number of a material being scanned by deriving transmission signal samples of the material being scanned, determining a variance of the signal samples, and determining an atomic number of the material being scanned by comparing the variance of the signal samples, or a derivative of the variance, to one or more predetermined variances.
Abstract:
The present invention provides an apparatus and method for measuring flow velocity of a multi-phase fluid mixture. The proposed apparatus (1) comprises radiation means (2), detecting means (3), and analysis means (3). The radiation means (2) generates a beam (11, 12) of photons to irradiate said mixture spatially over a section (19) of flow of the mixture. The detection means (3) is spatially configured to receive photons emanating from said the section (19) of flow of the mixture at different intervals of time, and provides an image of a spatial distribution of the received photons for each said interval of time. The analysis means (4) determines flow velocity of one or more phases of said mixture based on a temporal sequence of the images of the spatial distributions of the received photons.
Abstract:
A detector apparatus is described for scanning of and obtaining radiation data from an object and for example generating an image therefrom. The apparatus comprises a radiation detector system spaced therefrom to define a scanning zone and to collect in use a dataset of information about radiation incident at the detector after interaction with an object in the scanning zone and adapted to resolve such collected information spatially in two dimensions across a scan area and spectroscopically across a plurality of frequency bands in the spectrum of the source. The detector system is adapted to resolve such collected information spectroscopically in that it comprises a detector that exhibits a spectroscopically variable response across at least a part of the spectrum of the source; and is adapted to resolve such collected information spatially in that it comprises: a rastering module configured to divide the scanning area into a plurality of pixels in each of two dimensions; and a detector control means to move the detector across the scanning area to scan such pixels successively and thereby collect a dataset for each pixel. A method is described based upon use of the apparatus.