Abstract: The invention relates to an imaging system (17) like a computed tomography system for generating an image of an object. Spectral measured projection data and non-spectral measured projection data are generated by a detector (6) having spectral detection elements and non-spectral detection elements, and spectral estimated projection data are estimated by using a model material distribution which could have caused the non-spectral measured projection data and by simulating a measurement of the spectral estimated projection data based on the model material distribution. An image is reconstructed based on the measured and estimated spectral projection data. Using the spectral estimated projection data in addition to the spectral measured projection data can lead to high quality spectral imaging, especially high quality spectral computed tomography imaging, which uses a simplified detector not only having generally more complex spectral detection elements, but also having simpler non-spectral detection elements.

Abstract: A radiation detector (100) with a scintillator (102), a photosensor (104) and an electronics module (108) is proposed. The electronics module (108) has a current-to-frequency converter (110) with a charge integrator (112) for generating a pulsed signal in having a frequency correlating with a charge generated by the photosensor (104) during a measurement cycle. The electronics module (108) further comprises a current source (120) for generating a frequency offset of the pulsed signal, an interrupting device (134) for interrupting an integration of the charge by the charge integrator (112), and a logic module (124) for determining the frequency of the pulsed signal. Therein, the logic module (124) is configured for determining an off-state of a radiation (404) source and for triggering the interrupting device (134) upon determining the off-state of the radiation source (404).

Abstract: The invention relates to a method of Computed Tomography imaging comprising: a. Performing a single acquisition of image data from at least two contrast agents into a blood vessel network, a first contrast agent among said at least two contrast agents having been in said blood vessel network for a longer time than a second contrast agent among said at least two contrast agents, b. Processing said image data using K-Edge detection and/or iodine delineation to separate data associated with each contrast agents in order to obtain a concentration map of each contrast agent, c. Determining from said image data a first part of the blood vessel network comprising both the first contrast agent and the second contrast agent, and a second part of the blood vessel network comprising only the first contrast agent, d. Calculating a partial blood volume map of the first part of the blood vessel network based on the total amount of second contrast agent and on the concentration map of the second contrast agent, e.

Abstract: A radiation detector (100) with a scintillator (102), a photosensor (104) and an electronics module (108) is proposed. The electronics module (108) has a current-to-frequency converter (110) with a charge integrator (112) for generating a pulsed signal in having a frequency correlating with a charge generated by the photosensor (104) during a measurement cycle. The electronics module (108) further comprises a current source (120) for generating a frequency offset of the pulsed signal, an interrupting device (134) for interrupting an integration of the charge by the charge integrator (112), and a logic module (124) for determining the frequency of the pulsed signal. Therein, the logic module (124) is configured for determining an off-state of a radiation (404) source and for triggering the interrupting device (134) upon determining the off-state of the radiation source (404).

Abstract: A method of a virtual X-ray colonoscopy includes scanning (204) a dark-field contrast (144) insufflated colon lumen (140) with an X-ray scanner (110) configured for dark-field-contrast, which generates dark-field-contrasted projection data and attenuation projection data. The dark-field-contrasted projection data and the attenuation projection data are reconstructed (206) into one or more dark-field-contrasted images (148).

Abstract: A biomarker of lung condition can conventionally be obtained using a spirometer. A spirometer provides an estimate of the volume of air expelled by the lungs. This is a rather indirect biomarker of the staging of a lung condition, because a reduction in lung volume may only manifest itself at a point where symptoms are well advanced. A lung condition such as Chronic Obstructive Pulmonary Disorder (COPD) is typically not visible on conventional X-ray attenuation images, because the relevant tissue (alve-oli-bearing microstructured lung tissue) contains a lot of air. The X-ray dark- field can successfully indicate microstructure, such as lung alveoli. Therefore, imaging the lungs using the dark-field can provide information on the status of COPD.

Abstract: The present invention relates to a device (34) and a method (70) for determining a status of an X-ray tube (10) of an X-ray system (36). Due to ageing and/or wear of the X-ray tube, the spectrum of the X-ray radiation (30) provided by the X-ray tube may change over the operation time of the X-ray tube. The present invention therefore suggests evaluating spectrally different values detected with an X-ray detector arrangement (32) of the X-ray system. A reference data set representing a reference condition of the X-ray tube by a plurality of spectrally different reference-values (44) and a working data set representing an aged condition of the X-ray tube by a plurality of spectrally different working-values (46) of detected X-ray radiation are used to determine an equivalent filtration function for an filtration material influencing a source X-ray radiation (26) emitted by an anode (16) of the X-ray tube.

Abstract: The invention relates to an X-ray source (2) for an imaging device comprising at least three electrodes; a power supply configured to provide a primary gap voltage between a first (13) and a second (12) electrode among said at least three electrodes, said primary gap voltage having an AC component, causing a transport of electrons from the first electrode toward the second electrode; and a controller configured to supply a variable potential on a third electrode (14) among said at least three electrodes, wherein the X-ray source is configured to generate an X-ray beam with an energy spectrum based on the voltage difference between the first electrode and the second electrode, and wherein the controller is configured to set the variable potential on the third electrode to a value causing at least a partial blocking of said transport of electrons, whenever a predetermined condition is met.

Abstract: The invention relates to a CT imaging apparatus and a method for generating sectional images of an object such as a patient on a patient table. According to one embodiment, first projections (P) are generated along a first helical scanning path (Tr1) of a first X-ray source according to a sparse angular sampling scheme. Additional projections (Q1, Q2, R1) may dynamically be introduced along said first helical scanning path (Tr1) and/or along a second helical scanning path (Tr2) of an additional X-ray source based on the evaluation of previous projections (P1).

Abstract: The present invention relates to X-ray imaging. In order to reduce X-ray dose exposure during X-ray image acquisition, an X-ray detector is provided that is suitable for phase contrast and/or dark-field imaging. The X-ray detector comprises a scintillator layer (12) and a photodiode layer (14). The scintillator layer is configured to convert incident X- ray radiation (16) modulated by a phase grating structure (18) into light to be detected by the photodiode layer. The scintillator layer comprises an array of scintillator channels (20) periodically arranged with a pitch (22) forming an analyzer grating structure. The scintillator layer and the photodiode layer form a first detector layer (24) comprising a matrix of pixels (26). Each pixel comprises an array of photodiodes (28), each photodiode forming a sub-pixel (30). Adjacent sub-pixels during operation receive signals having mutually shifted phases.

Abstract: Methods and related apparatus (SP) to correct phase shift image data for phase wrapping artifacts. The data is detected at a detector (D) of an imaging system (IM) including interferometric equipment (G0, G1, G2). In a phase unwrapping method that involves optimizing an objective function with regularization, a two-sage approach is proposed. The measured data is processed in one stage with regularization and in the other stage without regularization. This allows improving the accuracy of the corrected (phase unwrapped) phase shift data because an undesirable bias caused by the regularization can be avoided.

Abstract: The invention relates to a CT image generation apparatus (10) for generating an image of a head. Transformations of a first CT image of the head are determined for different measured projection groups, wherein for a measured projection group a transformation is determined such that a degree of similarity between the measured projection group and a calculated projection group is increased, wherein the calculated projection group is calculated by transforming the first CT image in accordance with the transformation to be determined and by forward projecting the transformed first CT image. A motion corrected three-dimensional second CT image is reconstructed based on the measured projections and the transformations determined for the different measured projection groups. This allows providing a high quality CT image of the head, even if a patient cannot stop moving the head in case of, for instance, stroke.

Abstract: The present invention relates to improved assessment of a stenosis in a blood vessel in a body by comparing hemodynamic properties of the stenosed blood vessel with a substantially symmetric different blood vessel in the same body.

Abstract: An X-ray imaging apparatus with an interferometer (IF) and an X-ray detector (D). A footprint of the X-ray detector (D) is larger than a footprint of the interferometer (IF). The interferometer is moved in scan motion across the detector (D) whilst the detector (D) remains stationary. Preferably the detector is a 2D full field detector.

Abstract: An imaging system (100) includes a detector array (110) that detects radiation traversing an examination region. The detector array includes at least a set of non-spectral detectors (112) that detects a first sub-portion of the radiation traversing the examination region and generates first signals indicative thereof. The detector array further includes at least a set of spectral detectors (114) that detects a second sub-portion of the radiation traversing the examination region and generates second signals indicative thereof. The imaging system further includes a reconstructor (120) that processes the first and second signals, generating volumetric image data.

Abstract: An apparatus (T) and method for correcting detector (104) measurement data for errors caused by imperfections in the detector (104) that effect the accuracy of the detector readings.

Abstract: An image processing system comprising: an input port (IN) for receiving two input images acquired of an object. Respective contrast in said images encodes information on different physical properties of the object. The images being converted from a signal detected at a detector (D) of an imaging apparatus (IM). A differentiator of the image processing system forms respective differences from pairs of image points from the respective input images. An edge evaluator (EV) computes, based on said differences, an edge score for at least one of said pairs of image points. The score is based on a measure that represents or is derivable from a conditional noise likelihood function. The likelihood function is based on a probability density that models noise for said signal. Said score is output through an output port (OUT).

Abstract: The invention relates to a detection apparatus for detecting radiation. The detection apparatus comprises a GOS material (20) for generating scintillation light depending on the detected radiation (25), an optical filter (24) for reducing the intensity of a part of the scintillation light having a wavelength being larger than 650 nm, and a detection unit (21) for detecting the filtered scintillation light. Because of the filtering procedure relatively slow components, i.e. components corresponding to a relatively large decay time, of the scintillation light weakly constribute to the detection process or are not detected at all by the detection unit, thereby increasing the temporal resolution of the detection apparatus. The resulting fast detection apparatus can be suitable for kVp-switching computed tomography systems.

Abstract: A method includes performing a first pass of an iterative image reconstruction in which an intermediate first spectral image and an intermediate second spectral image are generated using an iterative image reconstruction algorithm, start first spectral and second spectral images, and initial first spectral regularization and second spectral regularization parameters, updating at least one of the initial first spectral regularization or second spectral regularization parameters, thereby creating an updated first spectral regularization or second spectral regularization parameter, based at least on a sharpness of one of the intermediate first spectral or second spectral images, and performing a subsequent pass of the iterative image reconstruction in which an updated intermediate first spectral and second spectral image is generated using the iterative image reconstruction algorithm, the intermediate first spectral and second spectral images, and the updated first spectral regularization and Compton scatter reg

Abstract: 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.