摘要:
The present invention provides an oxidative coupling procedure that allows efficient synthesis of novel cyclo[n]pyrrole macrocycles. Therefore, the present invention provides cyclo[n]pyrroles where n is 6, 7, 8, 9, 10, 11, or 12, and derivatives, multimers, isomers, and ion and neutral molecule complexes thereof as new compositions of matter. A protonated form of cyclo[n]pyrrole displays a gap of up to 700 nm between strong Soret and Q-like absorption bands in the electronic spectrum, demonstrating no significant ground state absorption in the visible portion of the electronic spectrum. Uses of cyclo[n]pyrroles as separation media, nonlinear optical materials, information storage media and infrared filters are provided.
摘要:
The invention relates to the field of X-ray differential phase contrast imaging. For scanning large objects and for an improved contrast to noise ratio, an X-ray device (10) for imaging an object (18) is provided. The X-ray device (10) comprises an X-ray emitter arrangement (12) and an X-ray detector arrangement (14), wherein the X-ray emitter arrangement (14) is adapted to emit an X-ray beam (16) through the object (18) onto the X-ray detector arrangement (14). The X-ray beam (16) is at least partial spatial coherent and fan-shaped. The X-ray detector arrangement (14) comprises a phase grating (50) and an absorber grating (52). The X-ray detector arrangement (14) comprises an area detector (54) for detecting X-rays, wherein the X-ray device is adapted to generate image data from the detected X-rays and to extract phase information from the X-ray image data, the phase information relating to a phase shift of X-rays caused by the object (18). The object (18) has a region of interest (32) which is larger than a detection area of the X-ray detector (18) and the X-ray device (10) is adapted to generate image data of the region of interest (32) by moving the object (18) and the X-ray detector arrangement (14) relative to each other.
摘要:
The present invention relates to differential phase-contrast imaging of an object. For increasing spatial resolution of an X-ray imaging system (2) the size of a detector pixel element (8) may be considered a limiting factor. Accordingly, it may be beneficial to increase the resolution of an apparatus (38) for phase-contrast imaging without further reducing the area of an individual pixel element (8). Accordingly, an apparatus (38) for phase-contrast imaging with improved sampling is provided, comprising an X-ray source (4), a first grating element G1 (24), a second grating element G2 (26) and an X-ray detector element (6) comprising a plurality of detector pixel elements (8), each detector pixel element (8) having a pixel area A. An object to be imagined (14) is arrangeable between the X-ray source (4) and the X-ray detector element (6). The first grating element G1 (24) as well as the second grating element G2 (26) are arrangeable between the X-ray source (4) and the X-ray detector element (6). The X-ray source (4), the first grating element G1 (24), the second grating element G2 (26) and the X-ray detector (6) are operatively coupled for acquisition of a phase-contrast image of the object (14). At least one of the first grating element G1 (24) and the second grating element G2 (26) comprise a first area A1 having a first grating pitch p1 and a second area A2 having a second grating pitch p2 different from the first grating pitch.
摘要:
X-ray devices for Phase Contrast Imaging (PCI) are often built up with the help of gratings. For large field-of-views (FOV), production cost and complexity of these gratings could increase significantly as they need to have a focused geometry. Instead of a pure PCI with a large FOV, this invention suggests to combine a traditional absorption X-ray-imaging system with large-FOV with an insertable low-cost PCI system with small-FOV, The invention supports the user to direct the PCI system with reduced FOV to a region that he regards as most interesting for performing a PCI scan thus eliminating X-ray dose exposure for scanning regions not interesting for a radiologist. The PCI scan may be generated on the basis of local tomography.
摘要:
An X-ray image acquisition apparatus employing phase-contrast imaging with enlarged field of view includes an X-ray source, an X-ray detector element having a detector size, a beam splitter grating and an analyzer grating. An object is arrangeable between the X-ray source and detector. The beam splitter grating and the analyzer grating are arrangeable between the X-ray source and detector. The X-ray source, the beam splitter grating, the analyzer grating and the X-ray detector are operatively coupled such that a phase-contrast image of the object is obtainable. The apparatus is configure to acquire a phase-contrast image having a field of view larger than the detector size. The X-ray detector element is displaceable where, by the displacement of the X-ray detector, a phase-contrast image of the enlarged field of view is obtainable.
摘要:
A lookup operation is performed in a translation look aside buffer based on a first translation request as current translation request, wherein a respective absolute address is returned to a corresponding requestor for the first translation request as translation result in case of a hit. A translation engine is activated to perform at least one translation table fetch in case the current translation request does not hit an entry in the translation look aside buffer, wherein the translation engine is idle waiting for the at least one translation table fetch to return data, reporting the idle state of the translation engine as lookup under miss condition and accepting a currently pending translation request as second translation request, wherein a lookup under miss sequence is performed in the translation look aside buffer based on said second translation request.
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:
The invention relates to a projection values processing apparatus (1) for processing acquired projection values. A first image is reconstructed from acquired projection values under consideration of a reconstruction assumption by a reconstruction unit (13). A simulated projection values determining unit (14) determines simulated projection values by simulating a projection through the reconstructed first image under consideration of the reconstruction assumption, and inconsistency values are determined for the acquired projection values by an inconsistency determining unit (15), wherein an inconsistency value is indicative of a degree of inconsistency of a respective acquired projection value with the reconstruction assumption, by comparing the acquired projection values and the simulated projection values. The inconsistency values can be used for different purposes, for example, improving the quality of a reconstructed image or indicating image elements being affected by an inconsistency between reconstruction assumption and acquired projection values.
摘要:
The invention relates to an imaging system for imaging an object. Projection data of the object are acquired by using a radiation source emitting primary radiation (14) from a primary focal spot (15) and unwanted secondary radiation (16) from secondary focal spots (17). A first image of the object is reconstructed from the acquired projection data, a forward projection of the secondary radiation through the first image is simulated for generating secondary projection data, and a second image is generated based on the acquired projection data and the secondary projection data. Since the secondary projection data, which can generally cause image artifacts, are determined, the reconstruction unit can consider these unwanted secondary projection data while reconstructing the second image, in order to reduce the influence of the secondary projection data on the reconstructed second image, thereby improving the image quality.
摘要:
A method includes reconstructing measured projection data using an iterative statistical reconstruction algorithm that reduces image artifact caused by differences in variances in projections of the measured projection data used to update a voxel of the image for one or more voxels of the image. A reconstructor includes a processor that reconstructs measured projection data using an iterative statistical reconstruction algorithm that reduces or mitigates image artifact caused by differences in variances in projections used to update a voxel of the image for one or more voxels of the image. A computer readable storage medium encoded with computer executable instructions, which, when executed by a processor of a computer, cause the processor to: reduce image artifact caused by differences in variances in projections used to update a voxel of an image for one or more voxels of the image using an iterative statistical reconstruction algorithm.