Abstract: The present approach relates to avoiding azimuthal blur in a computed tomography context, such as in dual energy imaging with fast kV switching. In accordance with certain aspects, the focal spot position is held stationary in the patient coordinate system within each respective view and the detector signals within the view are summed. In one embodiment, this results in the low and high energy views within the signal being collected from the same position within the patient coordinate system.

Abstract: CBCT including monolithic photon counting FPD for medical applications requiring real-time 3D imaging, like mammography, interventional guided procedures or external beam radiotherapy, includes CMOS processed readout electronics monolithically integrated with a single crystalline X-ray absorber by covalent wafer bonding near room temperature and adapted for single photon counting providing high energy, temporal and spatial resolution.

Abstract: According to an X-ray CT apparatus and a scanning method of the present invention, in order to efficiently create an image used for diagnosis, an operator selects a desired part from a part selection GUI before main scanning by using an ROI object imitating a shape of each part, held in a storage device, and thus the ROI object can be disposed on a scanogram image, in which setting information corresponding to a part is set for the ROI object in advance, a region of interest associated with the part is set, main scanning is performed under conditions associated with the set region of interest, and an image is reconstructed on the basis of X-ray information obtained through the main scanning.

Abstract: An X-ray CT apparatus includes processing circuitry. The circuitry controls a voltage generator during non-helical scan to switch tube voltage, thereby causing an imaging to be performed separately with X-rays of a first energy and X-rays of a second energy. The circuitry generates first and second projection data sets, respectively. The circuitry performs image reconstruction based on the first and second projection data sets respectively, thereby generating first and second images respectively. The circuitry performs alignment processing to align the second image with the first image. The circuitry generates a third projection data set based on a processing result of the alignment processing. The circuitry performs transformation processing to transform the second and third projection data sets into projection data sets corresponding to reference materials.

Abstract: Provided are an image acquisition device and an image acquisition method capable of acquiring the internal and external contours of a measured object with a high degree of accuracy.

Abstract: The present invention relates to a method and system for providing ‘diagnosis-aiding information’, the method and system being capable of diagnosing cancer and the like of a patient by using medical imaging.

Abstract: A computed tomography (CT) system includes a rotatable gantry having an opening to receive an object to be scanned, a high-voltage generator, an x-ray tube positioned on the gantry to generate x-rays through the opening, a pixelated detector positioned on the gantry to receive the x-rays, and a computer. The computer is programmed to obtain a scout image of the object, calculate an equivalent diameter of a water cylinder based on the scout image over a length of the scout image, calculate a major axis and a minor axis for an equivalent ellipse over the length, calculate, based on a noise index and based on the equivalent diameter as the function of the length, an mA modulation as a function of the length, and obtain image data of the object by modulating an mA applied to the x-ray tube based on the calculated mA modulation.

Abstract: A system includes acquisition of a spectral topogram of a target, determination, based on the spectral topogram, of an attenuation associated with each of a plurality of regions of the target and a composition of each of the plurality of regions, determination of imaging parameters associated with the plurality of regions based on the determined attenuation and composition, and acquisition of an image of the target based on the imaging parameters.

Abstract: A mobile radiography apparatus has a moveable (e.g., wheeled) transport frame and an adjustable column mounted at the frame. A boom apparatus supported by the adjustable column can support an x-ray source assembly. Radiation or X-ray source assembly methods and/or apparatus embodiments can provide mobile radiography carts a capability to direct x-ray radiation towards a subject from one or a plurality of different source positions, where the X-ray source assembly includes a first x-ray power source and a second plurality of distributed x-ray sources disposed in a prescribed spatial relationship.

Abstract: The present disclosure provides a decomposition method based on basis material combination. In the present disclosure, a scanned object is divided into a plurality of regions, the basis material combinations used in each of the divided regions are different each other, and the scanned object is re-divided according to the re-determined equivalent atomic number of its each point until the change on decomposition coefficient meets certain conditions. Thereby, a decomposition method based on dynamic basis material combinations is realized, which reduces a decomposition error caused by improper selection of the basis material combination and improves the accuracy of the decomposition and substance identification of the multi-energy CT.

Abstract: A correction method for a mask pattern is provided. The method includes providing a chip pattern region including a plurality of main features, and providing first auxiliary patterns around each main feature. The method also includes performing a first optical proximity correction to correct the main features into first correction features, and providing a plurality of detection regions. Each detection region is connected to an adjacent first correction feature via the first auxiliary pattern. In addition, the method includes performing an exposure process to obtain a light intensity distribution corresponding to each detection region after performing the exposure process. Moreover, the method includes correcting the first auxiliary patterns into second auxiliary patterns based on an auxiliary pattern correction model and the light intensity distribution of each detection region.

Abstract: An X-ray imaging method is for generating contrast-enhanced image data relating to an examination region of an object to be examined. In an embodiment of the method, first contrast-agent influenced measured X-ray projection data with a first X-ray energy spectrum and at least one set of second contrast-agent influenced measured X-ray projection data with a second X-ray energy spectrum are acquired from the examination region. Subsequently, image data assigned to a third X-ray energy spectrum with a third mean energy, based on the first and at least second measured X-ray projection data is reconstructed based on the first and at least second measured X-ray projection data that has been acquired. A mean energy of the first X-ray energy spectrum and a mean energy of the second X-ray energy spectrum are selected as a function of a dimension parameter value of the object that is to be examined.

Abstract: Some embodiments of the invention provide a method of determining a material characteristic of material in a sample by iterative tomographic reconstruction. The method conducts one or more X-ray tomography scans of a sample, and then determines one or more estimated material characteristics, such as atomic number and density, for multiple volume elements in the sample using a tomographic reconstruction algorithm. These estimated material characteristics are then modified by reference to stored known material characteristic data. Preferably, determining the composition of the sample volume during reconstruction includes segmenting the sample into regions of common composition, the segmenting being performed during iterative reconstruction instead of being based on the voxel characteristics determined upon the completion of iterative reconstruction.

Abstract: Provided herein is a radiography apparatus including an X-ray source configured to irradiate a subject radiation, and a sensing module configured to sense the radiation having passed through the subject, wherein the X-ray source includes a cathode electrode comprising an electric field emitting source configured to emit electrons, an anode electrode disposed opposite to the cathode electrode and configured to use the electrons to generate the radiation, and a current control unit connected to the cathode electrode to control an amount of the electrons.

Abstract: A method is for generating CT image data with spectral information from an examination region of a patient. According to an embodiment, the examination region is exposed to polychromatic X-radiation. Data from the examination region, including a first projection measurement data record and at least one second projection measurement data record, is captured via a photon counting detector. At least one second projection measurement data record with reduced resolution is generated based upon the at least one second projection measurement data record. The first and at least one second projection measurement data records are then transmitted to an image generation unit. Finally, the resolution of the first projection measurement data record is transferred onto the at least one second projection measurement data record with reduced resolution and/or an image data record based on the at least one second projection measurement data record with reduced resolution. A system is also disclosed.

Abstract: Methods and system for decomposing a high-energy dual-energy X-ray CT material are disclosed. In the method, two types of effect such as Compton effect and electron pairing effect which dominates are reserved and the influence of the other effect such a photoelectric effect is removed so as to improve the accuracy of the material decomposition. The unique advantage of the present disclosure is to effectively remove the error of the calculated atomic number Z due to directly selecting two effects during processes of material decomposition in the conventional dual-energy CT method. This may greatly improve the accuracy of dual-energy CT identification of the material, and it is important to improve the conventional dual-use CT imaging system applications, such as clinical therapy, security inspection, industrial non-destructive testing, customs anti-smuggling and other fields.

Abstract: In an X-ray scanning apparatus mounted with a photon counting type radiation detector, a data processing device of the X-ray scanning apparatus includes a correction unit that corrects a digital output value in each of the plurality of energy ranges with respect to each X-ray detection element in order to obtain an accurate projection image by correcting a counting error of the number of X-ray photons in each energy range. The correction unit includes an inflow amount calculation portion that calculates a digital amount corresponding to X-ray photons which flow from a certain X-ray detection element to another X-ray detection element, and an energy shift inflow amount/outflow amount calculation portion that calculates a digital amount corresponding to X-ray photons which flow into a high energy range due to energy shift in a single X-ray detection element, and performs correction by using the digital amounts calculated by the calculation portions.

Abstract: A segmentation-and-spectrum-based metal artifact reduction (MAR) system and method is applied in polychromatic X-ray CT system that uses a priori knowledge of high-Z metals in samples which contribute the primary artifacts at a known x-ray energy spectrum. Using a basis materials decomposition, the method solves the problem of reducing or eliminating metal artifacts associated with beam hardening using only a single scan of the sample performed at selected x-ray energy.

Abstract: A system includes memory (420) with instructions for at least one of processing spectral CT projection data to mitigate at least one of noise of the spectral CT projection data or a noise induced bias of the spectral CT projection data or generating a decomposition algorithm that mitigates the noise induced bias of the spectral CT projection data. The system further includes a processor (418) that executes the instructions and at least one of processes the spectral CT projection data or generates the decomposition algorithm and decomposes the spectral CT projection data to basis materials. The system further includes a reconstructor (434) that reconstructs the basis materials, thereby generating spectral images.

Abstract: There is provided a method for processing a radiographic image acquired with at least two energy levels. A first step (S1) involves providing energy-resolved image data representative of the radiographic image with at least two energy levels, e.g. from a detector or from an intermediate storage. A second step (S2) involves decomposing the provided image data into at least one basis image representation, based on a model where a combination of at least two basis functions is used to express a representation of at least one linear attenuation coefficient, and where at least one basis function models a physical material and at least one other basis function models the Non-Linear Partial Volume, NLPV, effect.

Abstract: The present disclosure relates to a multi-spectrum X-ray grating-based imaging system and imaging method. In one illustrative implementation, an exemplary multi-spectrum X-ray grating-based imaging system according to the present disclosure may comprise an incoherent X-ray source for emitting X-rays to irradiate an object to be detected, a grating module comprising a first absorption grating and a second absorption grating which are disposed in parallel to each other and are sequentially arranged in an X-ray propagation direction, and an energy-resolved detecting device for receiving the X-rays that have passed through the first absorption grating and the second absorption grating.

Abstract: A method displays spectral image data reconstructed from spectral projection data with a first reconstruction algorithm and segmented image data reconstructed from the same spectral projection data with a different reconstruction algorithm, which is different from the first reconstruction algorithm. The method includes reconstructing spectral projection data with the first reconstruction algorithm, which generates the spectral image data and displaying the spectral image data. The method further includes reconstructing the spectral projection data with the different reconstruction algorithm, which generates segmentation image data, segmenting the segmentation image data, which produces the segmented image data, and displaying the segmented image data.

Abstract: The present disclosure relates to a system, method and storage medium for generating an image. At least one processor, when executing instructions, may perform one or more of the following operations. When raw data is received, a plurality of iterations may be implemented. During each iteration, a first voxel value relating to a first voxel in an image is calculated; at least a portion of a second voxel may be continuously changed with respect to at least a portion of the first voxel value; the image may be transformed to a projection domain to generate an estimated projection based on the first voxel value and the second voxel value; a projection error may be obtained based on the estimated projection and the raw data; and the image may be corrected or updated based on the projection error.

Abstract: Provided is a photon counting CT device for estimating an exposure dose to a subject, precisely in a simple configuration, irrespective of a spectrum shape of X-rays being applied. An exposure dose derived from the X-rays with predetermined intensity is obtained in every energy range provided in advance, and held as exposure per band data. When an imaging condition is provided, X-rays are applied in accordance with the imaging condition thus provided, and a photon count (intensity) of the incident X-rays as to each energy range is obtained, in the shape of spectrum of the X-rays applied to a detector without placing the subject. The intensity of the incident X-rays is multiplied by the exposure per band, and the results as to all the energy ranges are added up. Accordingly, the exposure dose caused by the X-rays being applied in accordance with the provided imaging condition is estimated.

Abstract: An imaging system includes a computed tomography (CT) acquisition unit and a processing unit. The CT acquisition unit includes an X-ray source and a CT detector. The processing unit is configured to determine a voltage delivery configuration for the X-ray source based on at least one of a patient size, a clinical task, or scan parameters. The voltage delivery configuration includes at least one of a transition configuration or a voltage threshold. The transition configuration corresponds to a transition between a high voltage and a low voltage. Portions of acquired data acquired above the voltage threshold are grouped as high energy data and portions acquired below the voltage threshold are grouped as low energy data. The processing unit is also configured to implement the voltage delivery configuration on the CT acquisition unit, and to control the CT acquisition unit to perform an imaging scan using the determined voltage delivery configuration.

Abstract: A method and apparatus for determining PET scanning time are provided. According to an example of the method, a CT image is divided into multiple single-bed CT images according to bed information of bed positions for a PET scan, wherein the CT image is obtained by performing a CT scan on a subject of the PET scan, and a one-to-one corresponding relation exists between the multiple single-bed CT images and all of the beds. A residual true coincidence count ratio is estimated for each of the beds based on corresponding single-bed CT image of the bed, and then a scanning time proportion for each of the beds may be determined based on each of the residual true coincidence count ratios for the beds.

Abstract: There is provided a method for processing a radiographic image acquired with at least two energy levels. A first step (S1) involves providing energy-resolved image data representative of the radiographic image with at least two energy levels, e.g. from a detector or from an intermediate storage. A second step (S2) involves decomposing the provided image data into at least one basis image representation, based on a model where a combination of at least two basis functions is used to express a representation of at least one linear attenuation coefficient, and where at least one basis function models a physical material and at least one other basis function models the Non-Linear Partial Volume, NLPV, effect.

Abstract: A method and apparatus for selecting high and low energy scanning voltages for a dual energy CT scanner are provided. The method may comprise: setting a criterion of selection for selecting high and low energy scanning voltages; generating combinations of high and low energy scanning voltages according to all scanning voltages supported by a dual energy CT scanner, wherein each of the combinations may comprise a high energy scanning voltage and a low energy scanning voltage; and selecting a combination of high and low energy scanning voltages from the generated combinations of high and low energy scanning voltages based on the criterion of selection.

Abstract: An X-ray detector is disclosed, including a detection unit to generate a detection signal for incident X-ray radiation; a signal analysis module to determine a set of count rates for incident X-ray radiation based upon the detection signal and signal analysis parameters for X-ray radiation; and a switchover control unit for switching between first signal analysis parameters and second signal analysis parameters. When an amount of X-ray radiation is incident on the detection module, a first set of count rates is generated for a first time interval based upon first signal analysis parameters and a second set of count rates is generated for a second time interval based upon second signal analysis parameters, different from the first signal analysis parameters. An X-ray imaging system including the detector; a method for determining count rates for X-ray radiation; and a method for calibrating signal analysis parameters are also disclosed.

Abstract: Embodiments of methods and apparatus are disclosed for obtaining differential phase contrast imaging system and methods for same. Method and apparatus embodiments can provide regularized phase contrast retrieval that can address noise reduction and/or edge enhancement. Certain exemplary embodiments can suppress stripe artifacts occurring in the process of integration of noisy differential phase data. Further, certain exemplary embodiments can use transmission images and/or dark-field images to improve or restore phase contrast images affected by noise edges.

Abstract: An X-ray product quality online inspection device of the present invention comprises: a distributed X-ray source having a plurality of targets and being able to generate X-rays for irradiating an inspected product from the plurality of targets in a predetermined sequence; a detector for receiving the X-rays generated by the distributed X-ray source and outputting a signal representing characteristics of the received X-rays; a transport device which is located between the distributed X-ray source and the detector for carrying the inspected product to pass through an X-ray radiation region, wherein the transport device is arranged as a continuous transport mechanism which matches a production line of the inspected product; and a power supply and control device, which is used to supply power to and control the X-ray product quality online inspection device.

Abstract: A tomography imaging apparatus and a tomography imaging method are provided. The tomography imaging apparatus includes a data acquirer configured to acquire first X-ray data of an object for each of energy bands, and an image preprocessor configured to perform a beam hardening correction on the first X-ray data for each of the energy bands, to generate second X-ray data of the object. The tomography imaging apparatus further includes an image reconstructor configured to reconstruct a tomography image of the object based on the second X-ray data.

Abstract: A method includes determining a permeability metric of vascular tissue of interest based on a first time enhancement curve and second time enhancement curve corresponding to a first contrast material and a second contrast material flowing through the vascular tissue of interest and generating a signal indicative thereof.

Abstract: A mobile radiography apparatus has a moveable (e.g., wheeled) transport frame and an adjustable column mounted at the frame. A boom apparatus supported by the adjustable column can support an x-ray source assembly. Radiation or X-ray source assembly methods and/or apparatus embodiments can provide mobile radiography carts a capability to direct x-ray radiation towards a subject from one or a plurality of different source positions, where the X-ray source assembly includes a first x-ray power source and a second plurality of distributed x-ray sources disposed in a prescribed spatial relationship.

Abstract: An apparatus and method of processing X-ray projection data including spectral computed tomography (CT) projection data. The spectral CT data is decomposed into material projection lengths using a material-decomposition method that includes an initial-estimate method to provide an initial projection-lengths estimate. The initial-estimate method can include first reconstructing an image using non-spectral CT data, and then subdividing the reconstructed image into materials according to the relative attenuation density of areas within the reconstructed image (e.g., high attenuation areas correspond to a high attenuation material such as bone). The projection length estimates of each material are then obtained by forward projecting the corresponding subdivision of the reconstructed image. Also, the initial estimate can be obtained/refined by selecting the projection lengths with smallest cost-function value from randomly chosen projection lengths within a sample space.

Abstract: A method includes performing a contrast enhanced computed tomography (CT) scan of tissue of interest of a subject, with an imaging system (100) having a radiation source (112) and a detector array (118), in which a peak contrast enhancement of the tissue of interest, a full range of motion of the tissue of interest, and an entire volume of interest of the tissue of interest are concurrently imaged during a single rotation of the radiation source and the detector array of the imaging system over an entire or a predetermined sub-portion of a breathing cycle.

Abstract: The present invention is capable of distinguishing four types or more of substances such as air, water (soft tissues), contrast medium, and bones (calcification) to diagnose progress of atherosclerotic sites using dual energy imaging. A subject is imaged with two types of different tube voltages and an image obtained by image reconstruction is binarized to carry out a reprojection process; thereby, the distance of penetration of air is estimated, the contribution of air in measurement projection data is determined, and the amount of reduction by the air is deducted from the projection data so as to enable distinction between four or more substances such as air, water (soft tissues), contrast medium, and bones (calcification).

Abstract: A method is provided for evaluating a geological formation which integrates well data and high resolution computed tomography of rock samples thereof. Relationships are determined for a formation between a formation property, such as an elastic property, and at least one of photoelectric effect index (PEF), effective atomic number (Zeff), and bulk density (RHOB), using well data, and tomographic imaging is used to determine at least one of the latter mentioned properties (PEF, Zeff, RHOB) at higher resolution, which can be used in the relationship to determine a corresponding formation property. This affords an opportunity to develop formation property data for more challenging formations to evaluate, such as thinly laminated formations or others. Computerized systems, computer program products on non-transitory computer usable storage media, and programs for performing the methods are also provided.

Abstract: Among other things, one or more techniques and/or systems are described for correcting projection data generated from a computed tomography (CT) examination of an object and/or for computing or updating a CT value of the object from the projection data. An image generator is configured to generate a CT image of an object under examination. Using this CT image, a set of actions are performed to correct projection data from which the CT image was generated and/or to update a CT value of one or more voxels within the CT image. In this way, the projection data and/or CT image is adjusted to reduce image artifacts and/or otherwise improve image quality and/or object detection.

Abstract: A radiation imaging apparatus that includes a plurality of sensors and a control unit, wherein the control unit performs a first control of monitoring, after a radiation irradiation is started, a signal of a first sensor and accumulating the monitored signal of the first sensor, a second control of outputting, in response to a calculated value obtained by the accumulation and reaching a target value, a control signal to end the radiation irradiation, and a third control of reading out, after the radiation irradiation is ended, the signals of the respective plurality of sensors, and the control unit changes a monitoring cycle of the first control based on the target value and an elapsed time since the radiation irradiation has been started.

Abstract: A medical data processing method for determining a change in the position of a soft tissue body part of a patient's body, the data processing method being constituted to be executed by a computer and comprising the following steps: a) acquiring (S10, S20) bony body part planned position data comprising bony body part planned position information describing a planned position of a bony body part of the patient's body; b) acquiring (S10, S20) soft tissue body part planned position data comprising soft tissue body part planned position information describing a planned position of the soft tissue body part; c) acquiring (S11, S21) bony body part actual position data comprising bony body part actual position information describing an actual position of the bony body part; d) acquiring (S11, S21) soft tissue body part actual position data comprising soft tissue body part actual position information describing an actual position of the soft tissue body part; e) determining (S12, S22), based on the bony body part pla

Abstract: Embodiments of the disclosure include methods, machines, and non-transitory computer-readable medium having one or more computer programs stored therein to enhance core analysis planning for a plurality of core samples of subsurface material. Embodiments can include positioning electronic depictions of structure of encased core samples of subsurface material on a display and determining portions of each of the images as different planned sample types thereby to virtually mark each of the images. Planned sample types can include, for example, full diameter samples, special core analysis samples, conventional core analysis samples, and mechanical property samples. Embodiments further can include transforming physical properties of encased core samples of subsurface material into images responsive to one or more penetrative scans by use of one or more computerized tomography (CT) scanners.

Abstract: In the present embodiments, a statement related to an image point or an image region in a reconstructed x-ray image is made in relation to the reliability of the reconstructed grayscale value for the image points of a 2D/3D x-ray image. A confidence level is formed for the grayscale value from a first number of the available x-ray images in relation to a second number of required x-ray images for a complete reconstruction of the respective grayscale value of the 2D/3D x-ray image to be imaged.

Abstract: An apparatus is provided that includes a digital processing circuit to obtain a digital signal corresponding to an output signal of a photon-counting detector; determine, from the obtained digital signal, a plurality of X-ray photons received by the photon-counting detector during a measurement period; determine a corresponding energy level of each of the plurality of X-ray photons; determine, based on the corresponding energy level, a corresponding weight for each of the plurality of X-ray photons; and calculate a sum of the corresponding weights of the plurality of X-ray photons.

Abstract: A digital radiographic detector uses predetermined calibration information corresponding to a first operating temperature of the detector. The calibration data is accessible by the detector to compensate a radiographic image captured by the detector at a second operating temperature different than the first operating temperature. The operating temperature of the detector is monitored at approximately the time at which the radiographic image is captured at the second temperature.

Abstract: The following generally relates to scaling irregularity maps based at least on one of a histogram bin width, an image noise or a contrast agent concentration. A method includes obtaining a non-scaled irregularity map generated based on local weighted histograms of voxel distributions about voxels of interest from volumetric image data of a subject or object. The local weighted histograms include a plurality of bins having a predetermined bin width. The local weights are determined based on a predetermined cluster length. The method further includes scaling the non-scaled irregularity map, generating a scaled irregularity map. The non-scaled irregularity map is scaled based at least on the histogram bin width.

Abstract: A radiation imaging apparatus includes a plurality of conversion elements configured to convert radiation into an electric signal to obtain a radiation image, a sensor for monitoring radiation, a processing unit configured to process signals output from output electrodes of the plurality of conversion elements and an output electrode of the sensor, and a shield. The signal output from the output electrode of the sensor is supplied to the processing unit via a signal line. The shield is arranged such that capacitive coupling between the output electrodes of the plurality of conversion elements and the signal line is reduced.

Abstract: A method of presenting higher dimensional data provided from a photon counting CT system includes receiving data from a photon counting CT system corresponding to materials exposed to N number of ranges of photon energy, where N is a number equal to or greater than four and generating N number of images, each image comprising pixel values corresponding to the materials exposed to the N number of ranges of photon energy. The method also includes presenting the pixel values in each of the N number of images within a two dimensional (2D) space by providing N number of axes, each axis linearly representing the pixel values in a corresponding image of the N number of images and representing each pixel value for pixels corresponding to a same location in each of the N number of images via a continuous line comprising a plurality of line segments.

Abstract: A method for performing reconstruction for a region of interest (ROI) of an object is provided. The method includes designating the ROI within the object, the ROI being located within a scan field of view (FOV) of a combined third- and fourth-generation CT scanner, the CT scanner including fixed photon-counting detectors (PCDs), and an X-ray source that rotates about the object in synchronization with a rotating detector. Further, the method includes determining, for each PCD, as a function of view angle, an on/off timing schedule, based on a size and location of the designated ROI, and performing a scan to obtain a first data set from the rotating detector and a second data set from the plurality of PCDs, while turning each PCD on and off according to the determined schedule. Finally, the method includes performing reconstruction using the first and second data sets to obtain ROI spectral images.

Abstract: Spectral x-ray imaging using a photon counting x-ray detector (PCXD) transmits a broad spectrum x-ray beam through an object, detects the transmitted x-ray beam with the PCXD and processes the detected signals to determine material characteristics of the object using both the detected signals as a function of detector layer and the detected signals as a function of the particular energy band. Each detector layer of the multiple detector layers produces at least two signals, each signal representing a detected x-ray intensity in a particular energy band, and the depth information contained in the separate read-out channels.