Accuray Inc.

The University of Chicago

Zhicong Yu

Daniel Gagnon

Chuanyong Bai

Amit Jain

Jacob D Shea

Calvin R Maurer

Wenli Wang

Patrick Jean La Riviere

Phillip Vargas

Julian Bertini

Chuang Miao

Georgios Prekas

Robert Zahn

Marc Chappo

Jr Calvin R Maurer

Saturation in at least one saturated ray is in a method including identifying a saturated ray corresponding to a first ray of a radiation source received at a radiation detector after passing through a reference point during a current view of the radiation detector, identifying at least one non-saturated ray corresponding to a second ray of the radiation source received at the radiation detector, and responsive to the identifying, adjusting a value for the saturated ray based on a value of the at least one non-saturated ray. The non-saturated ray can be a ray from an adjacent view of a current rotation, an adjacent view of a previous or subsequent rotation, or a conjugate ray. Methods of selecting a gain level to avoid saturation are also disclosed.

Methods for saturation correction and dynamic gain configuration and apparatuses for performing the same

Disclosed herein is an imaging system including a first x-ray source configured to produce first x-ray photons in a first energy range suitable for imaging, project the first x-ray photons onto an area designated for imaging, a rotatable gantry configured to rotate the first x-ray source such that the first x-ray source traverses an angular path, and a data processor having an analytical portion. The analytical portion is configured to collect first data relating to the transmission of the first x-ray photons through the area designated for imaging at a set of image-collection angles along the angular path, collect background data at a set of background-collection angles along the angular path, wherein the system acquires more than one image of the designated area for imaging between background angles. The analytical portion is also configured to remove errors in the first data using the background data, and generate a corrected image based on the removal of errors in the first data.

Sparse background measurement and correction for improving imaging

An imaging apparatus comprises 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; and a first radiation detector coupled to the rotatable gantry system and laterally movable relative to a central beam of the first source of radiation to receive radiation from at least the first source of radiation over various fields of view. Alternative configurations of the imaging apparatus and methods of using the imaging apparatus are also provided.

Multimodal radiation apparatus and methods

A radio therapy system includes a first x-ray source. The first x-ray source is configured to produce first x-ray photons in a first energy range suitable for imaging and project the first x-ray photons onto an area designated for imaging. The system includes a second x-ray source configured to produce second x-ray photons in a second energy range higher energy than the first energy range, produce third x-ray photons in a third energy range higher energy than the first energy range, project the second x-ray photons onto the area designated for imaging, and project the third x-ray photons onto an area designated for treatment. The system includes an analytical portion configured to collect and combine data to create a composite output including at least one image, the combining based in part on a spectral analysis.

Radiotherapy apparatus and methods for treatment and imaging using hybrid MeV-keV, multi-energy data acquisition for enhanced imaging

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.

Multi-pass computed tomography scans for improved workflow and performance

Multimodal imaging apparatus and methods include a rotatable gantry system with multiple sources of radiation comprising different energy levels (for example, kV and MV). Fast slip-ring technology and helical scans allow data from multiple sources of radiation to be combined or utilized to generate improved images and workflows, including for IGRT. Features include large field-of-view (LFOV) MV imaging, kV region-of-interest (ROI) imaging, and scalable field-of-view (SFOV) dual energy imaging.

Apparatus and methods for scalable field of view imaging using a multi-source system

A method of scanning parameter optimization, which method may be useful with image-guided radiation therapy (IGRT), allows for controlling exposure of a beam from an x-ray source and/or controlling the detection mechanism for an x-ray detector of imaging radiation of a radiation-delivery device based on one or more parameters of a region of interest of a patient. The one or more parameters of the region of interest may include a dimension, outer contour, density, location relative to an outlet of the beam, location relative to isocenter, location to the whole patient body, etc. Exposure of the patient to the beam may be varied via modulation of one or more scanning parameters for controlling an aspect of the beam and/or the detector to provide for targeted and or reduced radiation exposure of the patient or portion of the patient, and/or for improved quality of guiding images. The modulation may be varied depending on a view angle of the region of interest from a portion of the radiation-delivery device.

Optimized scanning methods and tomography system using region of interest data

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.

Computed tomography system and method for image improvement using prior image

An x-ray imaging apparatus and associated methods are provided to receive measured projection data in a primary region and measured scatter data in asymmetrical shadow regions and determine an estimated scatter in the primary region based on the measured scatter data in the shadow region(s). The asymmetric shadow regions can be controlled by adjusting the position of the beam aperture center on the readout area of the detector. Penumbra data may also be used to estimate scatter in the primary region.

Asymmetric scatter fitting for optimal panel readout in cone-beam computed tomography

An x-ray imaging apparatus and associated methods are provided to receive measured projection data from a wide aperture scan of a wide axial region and a narrow aperture scan of a narrow axial region within the wide axial region and determine an estimated scatter in the wide axial region using an optimized scatter estimation technique. The optimized scatter estimation technique is based on the difference between the measured scatter in the narrow axial region and the estimated scatter in the narrow axial region. Kernel-based scatter estimation/correction techniques can be fitted to minimize the scatter difference in the narrow axial region and thereafter applying the fitted (optimized) kernel-based scatter estimation/correction to the wide axial region. Optimizations can occur in the projection data domain or the reconstruction domain. Iterative processes are also utilized.

Method and apparatus for improving scatter estimation and correction in imaging

An imaging apparatus and associated methods are provided to efficiently estimate scatter during multi-fraction treatments for improved quality and workflow. Estimated scatter from one fraction during a treatment course can be utilized during subsequent fractions, allowing for measurements with higher scatter-to-primary ratios. The quality of scatter estimates can be maintained, while workflow improves and dosage decreases. Scan configuration limits can be utilized to maintain a minimum level of scatter measurement quality. Patient information can be monitored to ensure that prior fraction scatter estimates are still applicable to current patient status.

Method and apparatus for image reconstruction and correction using inter-fractional information

An x-ray imaging apparatus and associated methods are provided to process projection data from an offset detector during a helical scan, including view completion. The detector may be offset in the channel and/or axial direction. Projection data measured from a current view is combined with projection data measured from at least one conjugate view to reconstruct a target image. A two-dimensional aperture weighting scheme is used to address data redundancy.

Helical cone-beam computed tomography imaging with an off-centered detector

An imaging apparatus and associated methods are provided to receive measured projection data in a primary region and correct for scatter by processing the imaging data as two separate components: non-scatter-corrected data and scatter-only data. Separate image processing (e.g., reconstruction) allows for the use of individualized data processing, including filters, suited to the source data, thereby focusing on specific aspects of the source data, including, for example, noise and artifact reduction, resolution, edge preservation, etc. Combining the separately processed data results in an optimized balance of these aspects with improved image quality.

Noise and artifact reduction for image scatter correction

An x-ray imaging apparatus and associated methods are provided to receive measured projection data in a primary region and measured scatter data in a shadow region and determine an estimated scatter in the primary region during a current rotation based on the measured scatter data in the shadow region from a neighboring rotation. Coverage of the shadow region during the neighboring rotation overlaps the primary region during the current rotation. A beamformer is configured to adjust a shape of the radiation beam to create the primary and shadow regions on the detector, including an embodiment to follow the Tam-Danielson window during a helical scan.

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Highland Hts., OH, United States of America

Zhicong Yu