The invention relates to off-center detector X-ray tomography reconstruction of an image of an object on the basis of projection data acquired during a rotation of an X-ray source and the off-center detector around the object in two rotational passes of less than 360°, wherein a focus point of the X-ray beam travels along largely overlapping arcs (401, 402) in the two rotational passes, the off-center detector being positioned asymmetrically with respect to a central of the X-ray beam and a direction of a detector offset being reversed between the passes. According to the invention, redundancy weighting of the projection data with respect to a redundant acquisition of projection values during each of the rotational passes is made using a redundancy weighting function determined on the basis of a union of the arcs (401, 402).

A multimodal imaging apparatus, comprising a rotatable gantry system positioned at least partially around a patient support, a first source of radiation coupled to the rotatable gantry system, the first source of radiation configured for imaging radiation, a second source of radiation coupled to the rotatable gantry system, the second source of radiation configured for at least one of imaging radiation or therapeutic radiation, wherein the second source of radiation has an energy level more than the first source of radiation, and a second radiation detector coupled to the rotatable gantry system and positioned to receive radiation from the second source of radiation, and a processor configured to combine first measured projection data based on the radiation detected by the first detector with second measured projection data based on the radiation detected by the second detector, and reconstruct an image based on the combined data, wherein the reconstructing comprises at least one of correcting the second measured projection data using the first measured projection data, correcting the first measured projection data using the second projection data, and distinguishing different materials imaged in the combined data using the first measured projection data and the second measured projection.

According to some aspects, a monochromatic x-ray source is provided. The monochromatic x-ray source comprises an electron source configured to generate electrons, a primary target arranged to receive electrons from the electron source to produce broadband x-ray radiation in response to electrons impinging on the primary target, and a secondary target comprising at least one layer of material capable of producing monochromatic x-ray radiation in response to incident broadband x-ray radiation emitted by the primary target.

A method includes providing a target object and acquiring measured images of the target object. Each of the measured images is acquired by filtering radiation from the target object by a mask having multiple holes and detecting filtered radiation by a detector. The method further includes providing an estimated image of the target object and calculating an updating factor for each of the measured images. The calculating of the updating factor includes partitioning a mathematical representation of the mask into multiple first regions; for each of the first regions, deriving a separate forward projection from the estimated image of the target object and the respective first region; and comparing the respective measured image of the target object with the forward projections. The method further includes updating the estimated image of the target object based on the updating factors.

A computed tomography method seeking higher resolutions without imposing a dose increase is described. A mask (10) forms a plurality of X-ray beam lets (14) which are passed through a subject (6), and images are captured on X-ray detector (8). The subject (6) is moved with respect to the X-ray detector and mask, including a rotation around a y axis, and a computed tomography image is reconstructed from the plurality of measured datapoints. The beam lets (14) are of small size. FIGS. 4-8 are blurred, FIGS. 10, 11 and 16b contain too small letters/numbers.

A method of imaging reconstruction includes providing a detector and a collimator, operating the detector to acquire a measured image of a target object from photons passing through the collimator, partitioning the collimator such that the collimator can be represented by a first matrix, providing an initial estimated image of the target object, and calculating an estimated image of the target object based on the measured image and the first matrix. The calculating of the estimated image includes an iteration using the initial estimated image as a starting point. The method also includes partitioning the collimator such that the collimator can be represented by a second matrix larger than the first matrix, and calculating a refined estimated image of the target object based on the measured image and the second matrix. The calculating of the refined estimated image includes an iteration using the estimated image as a starting point.

A surgical frame and a radiation-mitigation system are provided. The surgical frame can be capable of reconfiguration before, during, or after surgery, and can include a main beam that can be rotated, raised/lowered, and tilted upwardly/downwardly to afford positioning and repositioning of a patient supported thereon. Furthermore, use of imaging techniques to facilitate imaging of anatomical structures of a patient before, during, and after surgery can be desirous. An emitter of such imaging techniques can be positioned under the main beam of the surgical frame. The radiation-mitigation system can serve to intercept/block and mitigate at least some of the scatter of the electromagnetic radiation from the emitter.

According to some aspects, a monochromatic x-ray source is provided. The monochromatic x-ray source comprises an electron source configured to generate electrons, a primary target arranged to receive electrons from the electron source to produce broadband x-ray radiation in response to electrons impinging on the primary target, and a secondary target comprising at least one layer of material capable of producing monochromatic x-ray radiation in response to incident broadband x-ray radiation emitted by the primary target.

An x-ray imaging apparatus and associated methods are provided to execute multi-pass imaging scans for improved quality and workflow. An imaging scan can be segmented into multiple passes that are faster than the full imaging scan. Data received by an initial scan pass can be utilized early in the workflow and of sufficient quality for treatment setup, including while the another scan pass is executed to generate data needed for higher quality images, which may be needed for treatment planning. In one embodiment, a data acquisition and reconstruction technique is used when the detector is offset in the channel and/or axial direction for a large FOV during multiple passes.

The present disclosure relates to a medical imaging system having an X-ray source, a detector and a processing system. The the X-ray source is collimated to produce a diverging beam of radiation and transmits X-rays through an object. The detector includes detector pixels arranged in at least one row and is operative to receive the X-ray energy of the X-rays after having passed through the object. The processing system is programmed to select an initial height of the object with respect to the X-ray source plane and determine an initial time delayed summation (TDS) shift frequency based on the initial height. The processing system performs a first scan of the object based on the TDS shift frequency and determines a new height of the object based on a beam angle and an overlap of adjacent images. A new TDS shift frequency is determined based on the new height of the object if the initial height and the new height are not substantially same. The processing system then performs a second scan of the object based on the new TDS shift frequency. The processing system is further programmed to generate an image of the object based on detected X-ray energy at the X-ray detector based on the first scan and the second scan.