摘要:
The invention relates to a radiation detector (200), particularly an X-ray detector, which comprises at least one sensitive layer (212) for the conversion of incident photons (X) into electrical signals. A two-dimensional array of electrodes (213) is located on the front side of the sensitive layer (212), while its back side carries a counter-electrode (211). The size of the electrodes (213) may vary in radiation direction (y) for adapting the counting workload of the electrodes. Moreover, the position of the electrodes (213) with respect to the radiation direction (y) provides information about the energy of the detected photons (X).
摘要:
Computed tomography (CT) systems are provided that utilize x-ray tube spectra in connection with the generation and/or interpretation of CT data. The disclosed systems and methods use x-ray tube spectra associated with CT systems to enhance contrast and/or image quality, e.g., by making use of energy selective detection techniques. The x-ray spectra may be determined in a variety of ways, e.g., incorporation of a spectral x-ray tube model into the CT system, using the output of Monte-Carlo simulations, and/or processing measured experimental spectral tube data for the CT system. The x-ray tube spectra is generally generated by and/or stored in a computer system associated with the CT system and may be used in support of an energy selective detective method and/or generation of spectral CT images.
摘要:
A detector array includes at least one direct conversion detector pixel (114-114M) configured to detect photons of poly-chromatic ionizing radiation. The pixel includes a cathode layer (116), an anode layer (118) including an anode electrode (118-118 M ) for each of the at least one detector pixels, a direct conversion material (120), disposed between the cathode layer and the anode layer, and a gate electrode disposed in the direct conversion material, parallelto and between the cathode and anode layers.
摘要:
The invention relates to an imaging apparatus (31) for imaging an object. A reconstruction unit (12) determines component projection data values, which correspond to, for example, a base material of the object, and reconstructs an image of the object based on the determined component projection data values. A component projection data value, which corresponds to a ray, is determined as a combination of weighted base functions, which depend on energy projection data values of the same ray and the orientation of the same ray. This allows considering a possible dependency of the corresponding decomposition on the orientation of the ray, thereby allowing the imaging apparatus to improve the quality of decomposing the provided energy projection data values into the component projection data values and thus of a finally reconstructed image of the object, which is reconstructed based on the component projection data values.
摘要:
An imaging system includes a radiation source (106, T1, T2, T3) that rotates about an examination region and emits radiation that traverses the examination region. The radiation source (106, T1, T2, T3) emits radiation having an energy spectrum that is selectively alternately switched between at least two different energy spectra during an imaging procedure. The system further includes an energy-resolving detector array (116, D1, D2, D3) that detects radiation traversing the examination region. The energy-resolving detector array (116, D1, D2, D3) resolves the detected radiation over at least two different energy ranges and produces energy-resolved output signals as a function of both emission energy spectrum and energy range. The system further includes a reconstructor (126) that performs a spectral reconstruction of the energy-resolved output signals. In another embodiment, the detector array (116) includes a photon-counting detector array (116).
摘要:
The invention relates to a computed tomography apparatus for imaging an object. The computed tomography apparatus comprises a radiation source (2) for generating modulated radiation (4) traversing the object and a detector (6) for generating detection values depending on the radiation (4) after having traversed the object, while the radiation source (2) and the object are moved relative to each other. A weight providing unit (14) provides modulation weights for weighting the detection values depending on the modulation of the radiation (4) and a reconstruction unit (15) reconstructs an image of the object, wherein the detection values are weighted based on the provided modulation weights and an image of the object is reconstructed from the weighted detection values. This can allow to optimize the dose application to the object by modulating the radiation accordingly, wherein the reconstructed images still have a high quality.
摘要:
A method for processing projection data in the projection domain includes receiving the projection data. The projection data is generated by a spectral detector and includes two or more independent energy-resolved measurements in which at least one of the two or more measurements has first photon statistics. The method further includes generating a de-noised measurement in electronic format for the at least one of the two or more measurements having the first photon statistics. The de-noised measurement has second photon statistics which are better than the first photon statistics.
摘要:
The invention relates to a computed tomography apparatus for imaging an object. The computed tomography apparatus comprises a radiation source (2) for generating modulated radiation (4) traversing the object and a detector (6) for generating detection values depending on the radiation (4) after having traversed the object, while the radiation source (2) and the object are moved relative to each other. A weight providing unit (14) provides modulation weights for weighting the detection values depending on the modulation of the radiation (4) and a reconstruction unit (15) reconstructs an image of the object, wherein the detection values are weighted based on the provided modulation weights and an image of the object is reconstructed from the weighted detection values. This can allow to optimize the dose application to the object by modulating the radiation accordingly, wherein the reconstructed images still have a high quality.
摘要:
A method includes analyzing a spectral projection image of a portion of a subject, generating a value quantifying an amount of a target specific contrast material in a region of interest of the spectral projection image, and generating a signal indicative of a presence of the target in response to the value satisfying a predetermined threshold level.
摘要:
A method includes detecting radiation that traverses a material having a known spectral characteristic with a radiation sensitive detector pixel that outputs a signal indicative of the detected radiation and determining a mapping between the output signal and the spectral characteristic. The method further includes determining an energy of a photon detected by the radiation sensitive detector pixel based on a corresponding output of the radiation sensitive detector pixel and the mapping.