Abstract: The present invention provides an X-ray CT apparatus for imaging an MD image having a better S/N. The X-ray CT apparatus for taking an image with one of two materials within a subject to be examined being fractionated, acquiring two sets of data corresponding to said two types of X-ray having different energy by scanning using said two types of X-ray, generating a first image based on the two sets of data with the pixel values made by weighted addition of two types of CT values corresponding to the two types of X-ray, generating a second image based on the two sets of data, wherein the other one of the two types of material being fractionated, and generating an image by weighted subtraction of the first image and the second image.

Abstract: The present invention is directed to a method and apparatus of multi-energy data acquisition. An imaging system is also provided and includes a number of HF electromagnetic energy filters. The filters include at least a first and a second filter wherein the first filter is positioned in a path of HF electromagnetic energy when an HF electromagnetic energy source is energized to a first voltage and the second filter is positioned in the path of HF electromagnetic energy when the HF electromagnetic energy source is energized to a second voltage.

Abstract: A computed tomography system includes an x-ray source (108) that rotates about and emits radiation through an imaging region (116). At least one finite energy resolution detector (112) detects the emitted radiation. The at least one finite resolution detector (112) includes a plurality of sub-detectors (204). Each of the plurality of sub-detectors (204) is associated with one or more different energy thresholds. Each of the energy thresholds is used to count a number of incident photons based on a corresponding energy level. A reconstruction system (136) reconstructs the photon counts to generate one or more images of a subject residing within the imaging region (116).

Abstract: By simultaneously administering a chemical using a nuclear species releasing a single photon (a first chemical) and another chemical using a nuclear species releasing a positron to a subject, the cumulative distributions of the respective chemicals are monitored. A plural number of ?-ray detectors, which are circularly located, and a collimator covering some of the ?-ray detectors and rotates along the front face of the ?-ray detectors are provided. Also, an energy discriminating means for discriminating signals having a single photon ?-ray energy (first signals) from signals having annihilation ?-ray energy (second signals) among all of the signals detected by the detectors is provided. Further, the cumulative position of the first chemical is specified based on the signals corresponding to the ?-ray detectors covered with the rotating collimator from the first signals.

Abstract: The photon counting type detector 122 includes a drift electrode 122a, an MSGC 122b provided at a prescribed interval and a drift region 122c formed by sealing gas between the drift electrode 122a and the MSGC 122b. The projection data outputted from the photon counting type detector 122 is discriminated by the discrimination circuit 162 for each of X-ray energies and a CT image is reconstructed based on the projection data after discrimination, thereby providing an energy discrimination type X-ray CT apparatus capable of improving image quality at lower cost.

Abstract: A Multi-Energy Computed Tomography (MECT) System is provided. The system includes a radiation source rotatable about a patient, a radiation detector, and a computer coupled to the radiation source and the radiation detector wherein the computer is configured to receive data regarding a first energy spectrum of a scan of a head of the patient, receive data regarding a second energy spectrum of a scan of the head, and generate an image using the received data.

Abstract: A computer tomography apparatus (100) for examination of an object of interest (107), the computer tomography apparatus (100) comprising detecting elements (123) adapted to detect electromagnetic radiation coherently scattered from an object of interest (107) in an energy-resolving manner, and a determination unit (118) adapted to determine structural information concerning the object of interest (107) based on a statistical analysis of detecting signals received from the detecting elements (123).

Abstract: The present invention relates to an X-ray imaging apparatus using a technique for preventing artifacts appearing in 3D X-ray images. The technique involves subtraction images obtained by an energy subtraction unit serving as the basis for a 3D reconstruction process for acquiring a 3D X-ray image selectively showing a site of interest in a patient. The technique also involves an image subtraction process carried out by the energy subtraction unit according to weights set by a weight setter which selects only the site of interest in the patient, and eliminates soft tissue forming a background around the site of interest. As a result, even if body motion occurs with the soft tissue forming the background around the site of interest of the patient while subtraction images are acquired one after another by the energy subtraction unit, the body motion in the soft tissue of the patient never appears as artifacts on the subtraction images, or on a 3D X-ray image acquired on the basis of the subtraction images.

Abstract: A diagnostic imaging system includes an x-ray source that emits a beam of x-ray energy toward an object to be imaged and an energy discriminating (ED) detector that receives the x-ray energy emitted by the x-ray energy source. The ED detector includes a first layer having a first thickness, wherein the first layer comprises a semiconductor configurable to operate in at least an integrating mode and a second layer having a second thickness greater than the first thickness, and configured to receive x-rays that pass through the first layer. The system further includes a data acquisition system (DAS) operably connected to the ED detector and a computer that is operably connected to the DAS. The computer is programmed to identify saturated data in the second layer and substitute the saturated data with non-saturated data from a corresponding pixel in the first layer.

Abstract: The reconstruction of the energy distribution at a detector with a detector element that consists of many small pixels, which count the number of photons above certain thresholds, is performed with a Maximum Likelihood analysis, according to an aspect of the present invention. Thus, the reconstruction scheme may use the redundancy in the measurement and may treat the Poisson statistics accordingly.

Abstract: A method of obtaining a computed tomography image of an object includes determining linear terms and non-linear beam hardening terms in a pair of line integral equations for dual-energy projection data from inserting average and difference from average attenuation terms, obtaining an initial solution of the line integral equation by setting the non-linear beam hardening terms to zero, and iteratively solving the line integral equations to obtain one line integral equations for each basis material. Attenuation by the first basis material corresponds to a photoelectric attenuation process, and attenuation by the second basis material corresponds to a Compton attenuation process. The line integral equations can be inverted by an inverse Radon procedure such as filtered backprojection to give images of each basis material. The images of each basis material can then be optionally combined to give monochromatic images, density and effective atomic number images, or photoelectric and Compton processes images.

Abstract: An x-ray computed tomography apparatus has a stationary unit and a rotatable unit, carrying an x-ray source and a radiation detector. The rotatable unit rotates around an axis relative to the stationary unit, that proceeds through both units. In order to transmit signals and measured data between the rotating unit and the stationary unit, transmitting/reception devices are mounted at each unit. The transmitting/reception devices transmit directed signals and are automatically oriented toward each other during relative movement caused by rotation of the rotating unit with respect to the stationary unit.

Abstract: A method for reducing noise in a computed tomographic (CT) image includes acquiring both a first set of projection views and a second set of projection views, wherein for each projection view in the first set of projection views there is an associated projection view in the second set of projection views representing the same object scanned at substantially the same time from substantially the same position. The method further includes reconstructing the first set of projection views and the associated second set of projection views to obtain a first image and a second image, respectively. Next, the first image and the second image are combined to obtain a noise map and an amount of noise in a product image is estimated utilizing the noise map. The method also includes filtering using the noise map to perform noise reduction.

Abstract: A multi X-ray generating apparatus which has a plurality of electron sources arranged two-dimensionally and targets arranged at positions opposite to the electron sources includes a multi electron source which includes a plurality of electron sources and outputs electrons from driven electron sources by selectively driving a plurality of electron sources in accordance with supplied driving signals, and a target unit which includes a plurality of targets which generate X-rays in accordance with irradiation of electrons output from the multi electron source and outputs X-rays with different radiation qualities in accordance with the generation locations of X-rays. The generation locations and radiation qualities of X-rays from the target unit are controlled by selectively driving the electron sources of the multi electron source.

Abstract: Conventional CSCT may require a complex reconstruction involving a large number of calculations. According to an exemplary embodiment of the present invention, additional collimators are used in combination with energy revolving detectors, which may allow that a CSCT image may be reconstructed by a simple superposition of images obtained from different viewing angles in a direct tomography data acquisition scheme. Advantageously, a reconstruction may be avoided. Advantageously, this may allow for an improved image quality while reducing an amount of calculations required for generating the output image.

Abstract: A system and method are disclosed for reconstructing contrast-enhanced CT images that are substantially free of beam-hardening artifacts. An imaging system includes a radiation source configured to project radiation toward an object to be scanned and an energy discriminating detector assembly having a plurality of detector elements and configured to detect radiation emitted by the radiation source and attenuated by the object to be scanned. The imaging system also includes computer programmed to count a number of photons detected by each detector element and associate an energy value to each counted photon and determine a material composition of a CT view from the number of photons counted and the energy value associated with each counted photon. The computer is also programmed to apply a weighting to the CT view based on the material composition of the CT view and reconstruct an image with differential weighting based on the weighting of the CT view.

Abstract: Acquisition techniques for dual energy (DE) chest imaging system. Technique factors include the added x-ray filtration, kVp pair, and the allocation of dose between low- and high-energy projections, with total dose equal to or less than that of a conventional chest radiograph. Factors are described which maximize lung nodule detectability as characterized by the signal difference to noise ratio (SDNR) in DE chest images. kVp pair and dose allocation are described using a chest phantom presenting simulated lung nodules and ribs for thin, average, and thick body habitus. Low- and high-energy techniques ranged from 60-90 kVp and 120-150 kVp, respectively, with peak soft-tissue SDNR achieved at [60/120] kVp for patient thicknesses and levels of imaging dose. A strong dependence on the kVp of the low-energy projection was observed.

Abstract: The present invention provides a material decomposition method capable of determining the distribution of density and constituent material concentration throughout an imaged object. The concentration, in the form of a mass fraction, mass percent, weight fraction, or weight percent, is determined from CT images acquired at different energy levels. The ratio of attenuation coefficients associated with one energy level to attenuation coefficients associated with another energy level is determined and used as an index in a lookup table to determine the concentration of a given material throughout the imaged object.

Abstract: An X-ray CT apparatus includes an X-ray generating section for generating X-rays with a plurality of X-ray tube voltages; a data collecting section for collecting, synchronously with a data collection signal, X-ray projection data from X-rays with each X-ray tube voltage switched by an X-ray tube voltage switching signal; and a control section for controlling a timed moment for switching of the X-ray tube voltage and a timed moment for start of data collection so that the timed moment for start of data collection at each X-ray tube voltage in the data collection signal is delayed relative to the timed moment for switching of the X-ray tube voltage to that X-ray tube voltage in the X-ray tube voltage switching signal by ?t1, ?t2 depending upon imaging conditions.

Abstract: A method for automatically inspecting a container for a target material using a computed tomography (CT) scanning system includes performing an initial radiographic scan of the container. Based at least partially on projection data generated during the initial radiographic scan, at least one location within the container is identified that requires CT inspection. A dual energy CT scan of the at least one identified location within the container is performed based on a single energy algorithm or a dual energy algorithm. The dual energy CT scan includes a low energy scan of the at least one identified location and a high energy scan of the at least one identified location. Based on dual energy scan information generated during the dual energy CT scan, a determination is made to confirm or clear an alarm corresponding to the at least one identified location within the container.

Abstract: In three-dimensional computed tomography or three-dimensional rotational X-ray imaging, the acquisition of different spectral measurement data requires subsequent acquisition runs. According to an exemplary embodiment of the present invention, an examination apparatus is provided in which different spectral measurement data are acquired immediately one after another during the same acquisition run by performing a focal spot switching during data acquisition. This may reduce motion artefacts.

Abstract: A method for calibrating and reconstructing material density images in a dual-spectral computed tomography (CT) system 100 is disclosed. An X-ray source in the CT system 100 emits a first X-ray spectrum and a second X-ray spectrum towards an object. The method includes computing calibration coefficients by using projection data from the object for the two X-ray spectra and by linearizing at least two basis materials such as bone and water simultaneously. Further, basis materials decomposition coefficients for the at least two basis materials are computed by linearizing the basis materials individually. Correction values for the projection data and for the basis materials are then computed by using the basis materials decomposition coefficients and the calibration coefficients. The computed correction values are used in reconstructing material density images for the basis materials.

Abstract: A new method extends iterated coordinate descent (“ICD”)—an optimization method employed in some statistical reconstruction algorithms—to handle material decomposition (“MD”) for energy discriminating computed tomography (“EDCT”) acquisitions.

Abstract: An energy-sensitive computed tomography system is provided. The energy-sensitive computed tomography system includes an X-ray source configured to emit an X-ray beam resulting from electrons impinging upon a target material. The energy-sensitive computed tomography system also includes an object positioned within the X-ray beam. The energy-sensitive computed tomography system further includes a detector configured to receive a transmitted beam of the X-rays through the object. The energy-sensitive computed tomography system also includes a filter having an alternating pattern disposed between the X-ray source and the detector, the filter configured to facilitate measuring projection data that can be used to generate low-energy and high-energy spectral information.

Abstract: A method includes simultaneously collecting both x-ray count data and energy charge data from a single cell.

Abstract: A method includes placing received x-rays into at least three bins.

Abstract: A system and method for creating a combined or mixed-energy image using both low- and high-energy CT data sets acquired using a dual-energy CT system. The low- and high-energy datasets are mixed using desired weighting factors to mimic a “single-energy” image. The low-energy dataset provides data with improved contrast enhancement, but with increased noise level. The high-energy dataset provides data with lower contrast enhancement, but with better noise properties. By combining the low- and high-energy datasets in accordance with the present method, the resulting mixed-energy images utilize the information of full dose of radiation used in the dual-energy scan. A plurality of weighting metrics can be selected, including patient size, dose partitioning, or image quality, to determine the desired weighting factors based on the weighting metrics. By selecting the proper weight factors, image noise can be reduced and/or the contrast to noise ratio can be increased in the mixed-energy image.

Abstract: A diagnostic imaging system includes an x-ray source that emits a beam of x-ray energy toward an object to be imaged and an energy discriminating (ED) detector that receives the x-ray energy emitted by the x-ray energy source. The ED detector includes a first layer having a first thickness, wherein the first layer comprises a semiconductor configurable to operate in at least an integrating mode and a second layer having a second thickness greater than the first thickness, and configured to receive x-rays that pass through the first layer. The system further includes a data acquisition system (DAS) operably connected to the ED detector and a computer that is operably connected to the DAS. The computer is programmed to identify saturated data in the second layer and substitute the saturated data with non-saturated data from a corresponding pixel in the first layer.

Abstract: A method of diagnostic imaging is disclosed herein. The method includes acquiring CT projection data at a first x-ray energy level and a second x-ray energy level. The method includes reconstructing a first image pair using a basis material decomposition algorithm and the CT projection data. The method includes displaying a first image from the first image pair. The method includes transforming the first image pair into a second image using image data from the first image pair. The method also includes displaying a second image. A CT system is also disclosed.

Abstract: An X-ray CT apparatus includes an X-ray radiation unit which applies a first X-ray having a first energy spectrum and a second X-ray having a second energy spectrum different from the first energy spectrum to a subject, an X-ray data acquisition unit which acquires first X-ray projection data of the subject based on the first X-ray and second X-ray projection data of the subject based on the second X-ray, and an image reconstruction unit which determines information about a difference between the first X-ray and the second X-ray with respect to an image of the subject, segments the image into at least two pixel areas based on the difference information, and sets part of the segmented pixel areas to a dual energy image obtained by a weighted subtraction process based on X-ray projection data having a plurality of energy spectrums.

Abstract: The present invention refers to a radiation system (1) comprising an excentric gantry (100) arranged in connection with multiple treatment rooms (61-68) separated by radiation-shielding separating members (71-78). A movable rotation head (120) is connected to the gantry (100) and is able to move between, and direct a radiation beam (110) into, the treatment rooms (61-68). A simulator head (200-1 to 200-8) is preferably arranged together with the radiation system so it can be used in each respective treatment room (61-68). In such a case, while a first subject (40-1) is being irradiated in a first room (61), a treatment set-up procedure, including correct positioning of subjects (40-2 to 40-8) and irradiation simulation, can simultaneously take place for the other subjects (40-2 to 40-8) in the other treatment rooms (62 to 68).

Abstract: An X-ray CT apparatus includes an X-ray irradiation unit for applying X-rays based on a first X-ray tube voltage and X-rays based on a second X-ray tube voltage to a subject by being switched every one view, a projection data acquisition unit for acquiring projection data by which X-ray tube voltage information about the applied X-rays are identified, and an image reconstruction unit for identifying first energy projection data based on the first X-ray tube voltage, second energy projection data based on the second X-ray tube voltage, and transient energy projection data acquired upon switching between the first and second X-ray tube voltages based on the X-ray tube voltage information, the image reconstruction unit including a conversion processor that converts the transient energy projection data to another data using the transient energy projection data and performs image reconstruction using the data subsequent to the conversion process.

Abstract: Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether there are drugs concealed in the inspected liquid article based on the difference between the acquired physical attributes and reference physical attributes of the inspected liquid article. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.

Abstract: A CT system includes a rotatable gantry having an opening for receiving a subject to be scanned, a rotatable gantry having an opening for receiving a subject to be scanned, an x-ray source configured to project x-rays having multiple energies toward the subject, and a generator configured to energize the x-ray source to a first voltage and configured to energize the x-ray source to a second voltage, the first voltage distinct from the second voltage. The system further includes a controller configured to cause the generator to energize the x-ray source to the first voltage for a first duration, acquire imaging data for at least one view during at least the first duration, after the first duration, cause the generator to energize the x-ray source to the second voltage for a second duration, and acquire imaging data for two or more views during at least the second duration.

Abstract: A method and an image evaluation unit are disclosed for recognizing and marking contrast agents in blood vessels of the lung with the aid of a CT examination using at least two different x-ray energy spectra.

Abstract: The invention concerns radiographic equipment for forming an image of an interior of an object. The equipment comprises a source of X-ray or gamma-ray radiation having two or more energies and operable to irradiate an object to be scanned and a radiation source producing neutrons operable to irradiate the object. The equipment also comprises a radiation detector array having a plurality of pixels, each sensitive to and arranged with respect to the X-ray or gamma-ray radiation source and the neutron producing radiation source and operable to measure the intensity of each type of radiation transmitted through the object; means to process the intensity of each type of radiation, to determine the attenuation of each type of radiation having passed through the object, and to form an image indicative of the shape and composition of the object's interior.

Abstract: A system and method of a diagnostic imaging system includes an x-ray source that emits a beam of x-rays toward an object to be imaged, a detector that receives x-rays emitted by the x-ray source and attenuated by the object, and a data acquisition system (DAS) operably connected to the detector. A computer is operably connected to the DAS and programmed to obtain a number of measurements of energy-sensitive CT measurements in excess of a number of materials to be resolved, decompose the number of measurements into individual materials as an overdetermined system of equations, and generate an image of the individual materials based on the decomposition.

Abstract: A system and method of a diagnostic imaging system includes a high frequency electromagnetic energy source that emits a beam of high frequency electromagnetic energy toward an object to be imaged, a detector that receives high frequency electromagnetic energy emitted by the high frequency electromagnetic energy source and attenuated by the object, a data acquisition system (DAS) operably connected to the detector, and a computer operably connected to the DAS. The computer is programmed to obtain CT scan data with two or more incident energy spectra, decompose the obtained CT scan data into projection CT data of two or more basis materials, reconstruct linearly weighted projections of the two or more basis materials, determine an optimized energy for the two or more basis materials within a region-of-interest (ROI), and form a monochromatic image of the projection CT data at the optimized energy using the two or more basis material projections.

Abstract: A detector module, in at least one embodiment, is disclosed for x-radiation or gamma radiation that includes one or more optical waveguide sections that are arranged next to one another in order to form one or more detector rows and are optically interconnected in serial fashion. The waveguide sections include one or more converter materials for converting incident x-radiation or gamma radiation into optical radiation and are designed in such a way that optical radiation of different wavelength is generated in respectively neighboring regions along the waveguide sections upon incidence of x-radiation or gamma radiation. The present detector module, in at least one embodiment, can be implemented cost effectively with a high number of detector rows, and is of very low weight.

Abstract: Stationary x-ray digital breast tomosynthesis systems and related methods are disclosed. According to one aspect, the subject matter described herein can include an x-ray tomosynthesis system having a plurality of stationary field emission x-ray sources configured to irradiate a location for positioning an object to be imaged with x-ray beams to generate projection images of the object. An x-ray detector can be configured to detect the projection images of the object. A projection image reconstruction function can be configured to reconstruct tomography images of the object based on the projection images of the object.

Abstract: The present invention provides an X-ray CT apparatus for imaging an MD image having a better S/N. The X-ray CT apparatus for taking an image with one of two materials within a subject to be examined being fractionated, acquiring two sets of data corresponding to said two types of X-ray having different energy by scanning using said two types of X-ray, generating a first image based on the two sets of data with the pixel values made by weighted addition of two types of CT values corresponding to the two types of X-ray, generating a second image based on the two sets of data, wherein the other one of the two types of material being fractionated, and generating an image by weighted subtraction of the first image and the second image.

Abstract: An apparatus receives signals generated by a detector (100) sensitive to ionizing radiation such as x-rays. A differentiator (204) generates an output indicative of the rate of change of the detector signal. A discriminator (206) classifies the amplitude of the differentiator (204) output. An integrator (208) triggered by the output of the discriminator (206) generates outputs indicative of the detected photons. One or more correctors (24a, 24b) corrects for pulse-pileups, and a combiner (25) uses the outputs of the correctors (24a, 24b) to generate an output signal indicative of the number and energy distribution of the detected photons.

Abstract: A method for associating EKG waveform data with computed tomography image data using a data synchronization scheme including generating the EKG waveform data using an electrocardiogram device, operating a computed tomography imaging system so as to create the computed tomography image data, communicating an exposure marker-in signal to the electrocardiogram device such that the exposure marker-in signal is associated with the EKG waveform data and processing the computed tomography image data, the EKG waveform data and the exposure marker-in signal, so as to correlate the EKG waveform data with the computed tomography image data. Also claimed is a medium encoded with a machine-readable computer program code for associating EKG waveform data with image data generated by an imaging system using a data synchronization scheme, the medium including instructions for causing controller to implement the aforementioned method.

Abstract: According to this invention, subtraction images obtained by an energy subtraction unit 15 serve as the basis for a 3D reconstruction process for acquiring a 3D X-ray image selectively showing a site of interest in a patient M. In addition, an image subtraction process carried out by the energy subtraction unit 15 according to weights set by a weight setter 14 selects only the site of interest in the patient M, and eliminates soft tissue forming a background around the site of interest. As a result, even if body motion occurs with the soft tissue forming the background around the site of interest of the patient M while subtraction images are acquired one after another by the energy subtraction unit 15, the body motion in the soft tissue of the patient M never appears as artifacts on the subtraction images, or on a 3D X-ray image acquired on the basis of the subtraction images.

Abstract: An X-ray CT apparatus comprising a storage device which stores therein a first table where fat contents are respectively associated with the values of the ratios of CT numbers, a CT number measurement unit which irradiates an object with X-rays under a plurality of different irradiation conditions, and which obtains actually-measured CT numbers for the respective irradiation conditions, and a fat content extraction unit which calculates the ratio of the actually-measured CT numbers for the respective irradiation conditions, and which extracts the fat content corresponding to the ratio of the actually-measured CT numbers, by referring to the first table.

Abstract: An x-ray system is disclosed including a selector for finding an optimum combination between the contrast medium and the energy spectrum of an x-radiation for a scan to optimize the noise-to-contrast ratio. A method for creating X-ray images is also provided. The x-ray images are created with the aid of contrast media by taking into account an optimal combination between the contrast medium and the energy spectrum of an X-radiation used for a scan. A method for the use of a lanthanide-containing complex to produce a contrast medium for optimizing the combination between the contrast medium and the radiation to obtain a maximum contrast-to-noise ratio in an X-ray image is also provided.

Abstract: A CT system in an example comprises one or more high frequency electromagnetic energy sources, a detection assembly, a data acquisition system (DAS), and a computer. The one or more high frequency electromagnetic energy sources emit one or more beams of high frequency electromagnetic energy toward an object to be imaged. The detection assembly is capable of measuring a plurality of projection data at a same projection path that corresponds to a plurality of distinct incident energy spectra. The detection assembly comprises one or more energy discriminating (ED) detectors and/or one or more energy integration (EI) detectors that receive high frequency electromagnetic energy emitted by the one or more high frequency electromagnetic energy sources. The data acquisition system (DAS) is operably connected to the one or more ED detectors and/or the one or more EI detectors. The computer is operably connected to the DAS.

Abstract: A system and method of integrating a nuclear medicine imaging device such as a gamma camera with a patient handling system where the nuclear medicine imaging system does not prevent full access to the patient and does not interfere with the field of view of accompanying modalities accommodated by use of the patient handling system.

Abstract: A CT detector capable of energy discrimination and direct conversion is disclosed. The detector includes multiple layers of semiconductor material with the layers having varying thicknesses. The detector is constructed to be segmented in the x-ray penetration direction so as to optimize count rate performance as well as avoid saturation. The detector also includes variable pixel pitch and a flexible binning of pixels to further enhance count rate performance.

Abstract: In an X-ray CT apparatus for sequentially performing first and second scans of different control parameters by switching the control parameter of at least one of tube voltage and tube current of an X-ray tube on the same slice in a subject, the time interval between the first and second scans is shortened. A scan controller for performing a control on a whole scan starts transmitting the control parameter corresponding to the second scan to an X-ray controller for controlling the tube voltage and the tube current in an X-ray tube during the first scan without waiting for the end of the first scan (S27).