A radiotherapy delivery device is provided. The device includes a source of therapeutic radiation and a first detector positioned to receive radiation from the source of therapeutic radiation. The device also includes a source of imaging radiation and a second detector positioned to receive radiation from the source of imaging radiation. A collimator assembly is positioned relative to the second source of radiation to selectively control a shape of a radiation beam emitted by the second radiation source to selectively expose part or the whole of the second radiation detector. A reconstruction processor can be operatively coupled to the detector and configured to generate patient images based on radiation received by the second detector from the second source of radiation. The device is configured to move from one imaging geometry to another using all or part of the second detector.

A computed tomography (CT) system and method is provided. The CT system is used to carry out an image improvement method in which a prior or previously-acquired patient image can be used to supplement or otherwise improve an acquired CT image, wherein the acquired projection data representative of the acquired CT image might be truncated or otherwise incomplete/insufficient to accurately and stably recover the scanned object/patient.

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.

A method is for the reconstruction of an image data set from projection images of an examination object recorded at different projection directions with a computed tomography apparatus. In an embodiment, the method includes establishing an item of contour information describing a contour of at least one of the examination object and the additional object; enhancing projection data of the projection images via forward projection in regions in which at least one of the examination object and the additional object was not acquired; and reconstructing the image data set based upon the projection data enhanced. The examination object and the additional object are acquired from sensor data of at least one camera. Finally, an item of sensor information at least partially describing at least one of the is of the examination object and of the additional object being established and used for establishing the contour information.

The invention relates to off-center detector 3D X-ray or proton radiography reconstruction. Redundancy weighting with a steep weighting function around the iso-axis typically leads to artifacts in the reconstruction, for example, if inconsistencies between two nominal redundant projections occur, e.g. due to slightly incorrect detector calibration or scatter correction, etc. With the present invention, an approach is presented for overcoming or mitigating these problems.

The disclosure relates to systems and methods for iterative reconstruction. Raw data detected from a plurality of angles by an imaging device may be obtained. A first seed image may be generated by performing a filtered back projection on the raw data. A first air mask may be determined by performing a minimum value back projection (BP) on the raw data. One or more images may be reconstructed by performing an iterative reconstruction based on the first seed image, the first air mask, and the raw data.

A method for artifact correction in computed tomography, the method including: (1) acquiring a plurality of data sets associated with at least one low X-ray energy, and at least one high X-ray energy; (2) generating a plurality of preliminary images from the plurality of data sets; (3) identifying sources of an artifact source image; (4) forward projecting the artifact source image to produce artifact source data; (5) selecting and combining the plurality of data sets acquired in order to produce a new subset of data associated with the artifact, whereby to produce artifact reduced data; (6) generating a repaired data set to keep data sets associated with the low X-ray energy in artifact-free data and to introduce data sets associated with the high X-ray energy in regions impacted by an artifact; and (7) generating a final reduced artifact image from the repaired data set.

An image generation method of an interior CT includes the following steps: a step for obtaining interior CT projection data by measuring only all of quantum beams passing through a region of interest (ROI) in an inside of photographing object in a geometrical system for CT measurement; a step for obtaining partial entire projection data by measuring quantum beams passing through an entire of said photographing object from a segment in an outside of said photographing object in said geometrical system for CT measurement; and a processing step for exactly reconstructing said ROI upon basis of said interior CT projection data obtained and said partial entire projection data.

Methods and devices for reconstructing dual-energy CT images are provided. In one aspect, CT scan is performed with a high energy and a low energy periodically and alternatively changed on a scanning target, reconstruction data for a high-energy image of a current reconstruction position is obtained based on whether a circle of high-energy scan closest to the current reconstruction position of the scanning target is a full circle of scan, the high-energy image of the current reconstruction position is reconstructed according to the reconstruction data of the high-energy image; reconstruction data for a low-energy image of the current reconstruction position is obtained based on whether a circle of high-energy scan closest to the current reconstruction position of the scanning target is the full circle of scan, the low-energy image of the current reconstruction position is reconstructed according to the reconstruction data of the low-energy image.

One example method to reduce image artifacts, which may include obtaining measured projection data acquired using an imaging system. The measured projection data is associated with a target object and an artifact source within a radiation field of the imaging system. The method may also include generating virtual projection data associated with the artifact source by forward projecting a model representing one or more physical properties of the artifact source. The method may further include generating corrected projection data based on the measured projection data and the virtual projection data; and reconstructing the corrected projection data into reconstructed volume image data to reduce image artifacts caused by the artifact source.