The present invention provides autoradiography methods and systems for imaging via the detection of alpha particles, beta particles, or other charged particles. Embodiments of the methods and systems provide high-resolution 3D imaging of the distribution of a radioactive probe, such as a radiopharmaceutical, on a tissue sample. Embodiments of the present methods and systems provide imaging of tissue samples by reconstruction of a 3D distribution of a source of particles, such as a radiopharmaceutical. Embodiments of the methods and systems provide tomographic methods including microtomography, macrotomography, cryomicrotomography and cryomacrotomography.

A gantry includes two X-ray source rings and a detector ring. Each X-ray source ring includes a plurality of X-ray sources arrayed circumferentially. The detector ring is provided next to the X-ray source ring and includes a plurality of X-ray detectors arrayed circumferentially. Each of the plurality of X-ray detectors detects X-rays from the X-ray source ring. A data collection circuit collects raw data corresponding to the intensity of the detected X-rays. A reconstruction unit reconstructs the collected raw data into a CT image based on digital data.

A computed-tomography (CT) apparatus including a CT scanner including a rotating X-ray source, and a plurality of photon-counting detectors (PCDs) arranged in a fixed detector ring to capture incident X-ray photons emitted from the X-ray source. The plurality of PCDs includes a first plurality of first PCDs, each first PCD having a first collimator on a surface of the first PCD to block X-ray photons emitted from the X-ray source, the first collimator having openings of a first size, and a second plurality of second PCDs, each second PCD having a second collimator on a surface of the second PCD to block the X-ray photons emitted from the X-ray source, the second collimator having openings of a second size, the first size being different from the second size.

The present invention relates to determining baseline shift of an electrical signal generated by a photon detector (102) of an X-ray examination device (101). For this purpose, the photon detector comprises a processing unit (103) that is configured to determine a first crossing frequency of a first pulse height threshold by the electrical signal generated by the photon detector. The first pulse height threshold is located at a first edge of a noise peak in the pulse height spectrum of the electrical signal.

There is provided a method of image reconstruction based on energy-resolved image data from a photon-counting multi-bin detector or an intermediate storage. The method comprises processing (S1) the energy-resolved image data by performing at least two separate basis decompositions using different number of basis functions for modeling linear attenuation, wherein a first basis decomposition is performed using a first smaller set of basis functions to obtain at least one first basis image representation, and wherein a second basis decomposition is performed using a second larger set of basis functions to obtain at least one second basis image representation. The method also comprises reconstructing a first image based on said at least one first basis image representation obtained from the first basis decomposition, and combining the first image with information representative of said at least one second basis image representation.

Disclosed are methods and devices for estimating object scatter and/or internal scatter in a multi-level photon-counting x-ray detector, as well as x-ray tomographic imaging while correcting for object and internal scatter. The x-ray detector has at least two layers of detector diodes mounted in an edge-on geometry, e.g. designed for 1) estimating the object scatter contribution to the counts in a top layer of the at least two layers based on difference(s) in counts between the top layer and lower layer(s) under the assumption the object scatter has a slowly varying spatial distribution, and/or 2) estimating counts from reabsorption of photons that have Compton scattered inside the detector based on selectively blinding some detector elements from primary radiation by placing a highly attenuating beam stop on top of the detector elements, in lower layer(s) or in both top layer and lower layer(s), and measuring the counts in those detector elements.

Disclosed is a measurement method performed by a Computed Tomography, CT, system. The CT system includes an x-ray source and an x-ray detector array of photon counting edge-on detectors, wherein each edge-on detector has a number of depth-segments, also referred to as detector elements, arranged at different spatial locations in the direction of incoming x-rays. The method includes to apply a time offset measurement scheme that provides a time offset between measurement periods for at least two different detector elements located at different depths, wherein the time offset is chosen so that at least two measurement periods at least partially overlaps in time. Disclosed is also a corresponding CT system, a control unit for a CT system and a measurement circuit for a CT system. A computer program controlling a CT system is also disclosed. The disclosed technology provides for a higher sampling frequency in the angular direction.

A photon counting type X-ray computed tomography apparatus includes an X-ray tube, a detector, a raw data generating section, an information compression section, and a data transmission section. The X-ray tube is configured to irradiate an X-ray. The detector is configured to count photons derived from the irradiated X-ray. The raw data generating section is configured to collect results of counting performed by the detector and to generate, from the results of counting, raw data for each of a plurality of energy bands. The information compression section is configured to compare values of the raw data between the raw data generated respectively for the energy bands, and to perform information compression of each of the raw data. The data transmission section is configured to transmit the raw data compressed by the information compression.

Various aspects include methods for compensating for the effects of charge sharing among pixelate detectors in X-ray detectors by applying a correspondence factor to counts of X-ray photons in energy bins to estimate incident X-ray photon energy bins. The correspondence factor may be determined by determining an incident X-ray photon energy spectrum, adjusting the incident X-ray photon energy spectrum to account for an energy resolution of the pixelated detector, generating a charge sharing model for the adjusted incident X-ray photon energy spectrum based on a percentage charge sharing parameter of the pixelated detector, applying the charge sharing model to energy bins of the pixelated detector to estimate counts in each of the energy bins, and determining the correspondence factor by comparing the estimated counts in each of the energy bins to counts in the energy bins that would be expected for the adjusting the incident X-ray photon energy spectrum.

The invention relates to a system (31) for generating spectral computed tomography projection data. A spectral projection data generation device (6) comprising an energy-resolving detector generates spectral computed tomography projection databased on polychromatic radiation (4), which has been provided by a radiation device (2), after having traversed an examination zone (5), and a reference values generation device generates energy-dependent reference values based on radiation, which has not traversed the examination zone. A spectral parameter providing unit (12) provides a spectral parameter being indicative of a spectral property of the radiation device based on the energy-dependent reference values. In particular, spectral properties of the radiation device can be monitored over time, wherein this information can be used for, for instance, correcting the spectral computed tomography projection data, and/or, if undesired spectral properties of the radiation device are indicated, triggering a replacement of the radiation device.