Abstract:
The present invention relates to a detection device for detecting radiation emitted from a radiation source, wherein the detection device (6) comprises a detection surface (19) and lamellae (18) protruding from the detection surface (19), wherein the lamellae (18) comprise a first end portion (20) close to the detection surface (19) and a second end portion (21) remote from the detection surface (19) and wherein the first end portion (20) has a larger width than the second end portion (21). The invention relates further to a computed tomography apparatus comprising this detection device.
Abstract:
It is described a method and a CT system for measuring dual-energy X- ray attenuation data of an object. The CT system comprises a rotatable holder, an X-ray source comprising two different X-ray focus points, and an X-ray detection device comprising a plurality of detector elements exhibiting different spectral sensitivities. The method comprises the steps of (a) adjusting the X-ray source such that it emits X-rays originating a first focus point, (b) acquiring first attenuation data separately with first detector elements and with second detector elements, (c) moving the X-ray focus discretely to a second focus point, and (d) acquiring second attenuation data separately with both types of detector elements. Thereby the two focus points are spatially separated from each such that a first beam path originating from the first focus point penetrates a certain voxel within the object and impinges on a first detector element and a second beam path originating from the second X-ray focus point penetrates the same voxel and impinges on a second detector element.
Abstract:
In a CSCT material identification apparatus CT-information and differential scatter cross-sections are used for material identification. According to an aspect of the present invention, a material identification is provided which uses both the differential and the total scatter cross-sections. This may yield an improved material discrimination, i.e. a better detection rate and a lower false alarm rate.
Abstract:
A CSI system is described that uses pencil beams (40,42,44,46) through a sample (30) having a region of interest (32). Each coherent scatter spectrum of sample beams (40, 44) through the region of interest is subtracted by the spectra using respective reference beams (42, 46). The measurements are combined to determine features of the region of interest (32) whilst minimising the effect of features in the rest of the sample (30).
Abstract:
A reconstruction of data from CSCT data usually requires a long reconstruction time. According to the present invention, a filtered back-projection of CSCT data, wherein the CSCT data comprises a spectrum acquired by means of an energy resolving detector element is provided, wherein the filtered back-projection is performed along curved lines represented by the wave-vector transfer in the reconstruction volume. Advantageously, a reconstruction time may be reduced, while allowing for a good image quality.
Abstract:
The invention relates to a computed tomography apparatus (CT apparatus) for imaging by means of radiation having traversed an object to be examined (that is, directly transmitted radiation), as well as by means of radiation scattered by the object to be examined, which apparatus includes a radiation source (S), a detector arrangement (16) and a device whereby the radiation (41a) having traversed the object to be examined can be blocked at least to an extent that the intensity incident on the detector arrangement (16) does not substantially exceed the intensity of radiation (41b) scattered by the object (13) to be examined and incident on the detector arrangement (16). The invention enables the detection of scattered radiation (CSCT mode) which is not affected by crosstalk from the transmitted radiation, even when the detector arrangement does not satisfy severe requirements as regards crosstalk properties and/or is configured as a single-row detector arrangement.
Abstract:
The invention relates to A contrast agent for application to an examination area of an object that is to be examined, in particular a patient, for an X-ray examination of the examination area by means of X-ray radiation, characterized that the contrast agent comprises scattering particles to form elastically scattered X-rays. By means of the scattering particles, the examination area can be made visible in the detected signal compared to surrounding areas. Furthermore, the invention relates to a method of examining an object, in particular a patient, by means of elastically scattered X-ray radiation as claimed in claim 9, a method of producing a contrast agent as claimed in claim 12, and an apparatus for examining an object by means of elastically scattered x-ray radiation as claimed in claim 15.
Abstract:
The invention relates to a computed tomography apparatus (CT apparatus) for imaging by means of radiation having traversed an object to be examined (that is, directly transmitted radiation), as well as by means of radiation scattered by the object to be examined, which apparatus includes a radiation source (S), a detector arrangement (16) and a device whereby the radiation (41a) having traversed the object to be examined can be blocked at least to an extent that the intensity incident on the detector arrangement (16) does not substantially exceed the intensity of radiation (41b) scattered by the object (13) to be examined and incident on the detector arrangement (16). The invention enables the detection of scattered radiation (CSCT mode) which is not affected by crosstalk from the transmitted radiation, even when the detector arrangement does not satisfy severe requirements as regards crosstalk properties and/or is configured as a single-row detector arrangement.
Abstract:
For correcting differential phase image data 52, differential phase image data 52 acquired with radiation at different energy levels is received, wherein the differential phase image data 52 comprises pixels 60, each pixel 60 having a phase gradient value 62a, 62b, 62c for each energy level. After that an energy dependent behavior of phase gradient values 62a, 62b, 62c of a pixel 60 is determined and a corrected phase gradient value 68 for the pixel 60 is determined from the phase gradient values 62a, 62b, 62c of the pixel 60 and a model for the energy dependence of the phase gradient values 62a, 62b, 62c.
Abstract:
A method includes detecting transmission radiation, from an x-ray source, that traverses an inspection region and an object therein and emission radiation from a radioactive material in the object, generating a signal indicative of the detected radiation, energy resolving the detected radiation, and processing the energy resolved radiation to identify detected radiation that has energy corresponding to the radioactive material.