California Institute of Technology

Leland Stanford Junior University

University of California

Mayo Foundation for Medical Education and Research

Scott S Hsieh

Morteza Gharib

Jian Lu

Alexei Harvard

Francisco Pereira

Norbert Joseph Pelc

David Jeon

Jeremy Joseph Dahl

Marko Jakovljevic

A system for charge sharing compensation for a photon counting detector. A plurality of comparators, each configured to generate comparator output data based on a threshold value, a plurality of energy bins, each of the plurality of energy bins coupled to one of the plurality of comparators, and a coincidence logic coupled to two or more of the plurality of comparators and configured to receive comparator output data associated with two or more of a plurality of pixels. The comparator output data for each pixel indicates when a signal associated with the pixel crosses a threshold value. The coincidence logic is configured to generate a coincidence output when the comparator output data for a first pixel is received within a predetermined time interval of the comparator output data for a second pixel. The system includes a coincidence counting bin coupled to the coincidence logic and configured to receive the coincidence output and generate count data based on the coincidence output.

System and method for charge sharing compensation for X-ray photon counting detectors

Measuring local speed of sound for ultrasound by inducing ultrasound waves in a subject by focusing an ultrasound beam, using an ultrasound Tx transducer to propagate waves from a focal point to the surface, measuring a time of arrival of the waves using at least three single Rx transducer surface elements, signal traces recorded on individual Rx transducers are evenly sampled in time, an average speed of sound equals an arithmetic mean of local sound-speed values sampled along a wave path, each Rx transducer outputs a separate arrival time of the waves, computing a local speed of sound (c) of waves from an average speed of sound (c) using a computer that receives arrival times, where where c=d/T, dis the length a tissue traveled during one sampling period T, and using cto differentiate human disease, or with ultrasound measurements to differentiate degrees of human disease.

Local speed of sound estimation method for medical ultrasound

A device for performing tomosynthesis in real time is described. Multiple imaging sources (such as x-ray sources) may be energized in parallel and collimated towards a field of view. Objects within the field of view cast shadows onto one or more detectors. An imaging system may read the one or more detectors and acquire multiple views corresponding to the multiple imaging sources to produce a reconstructed image of an object of interest. From this reconstructed image, a target of the radiation therapy can be located, and the delivery of the radiation can be adjusted, as needed. The approach provides a real-time tomosynthesis design that can produce enhanced contrast for guidance of, for example, lung tumor treatment. Higher frame rates can be achieved to better compensate for changes in the position of the target during radiation therapy due to, for example, respiratory or cardiac motion.

Real-time, parallel x-ray tomosynthesis

Hardware and software configurations, optionally, for performing profilometry of an object are disclosed. An advantageous imaging device is described. An advantageous approach to determining imager position is also described. Each aspect described may be used independently of the other. Moreover, the teaching may find use in other fields including velocimetry, etc.

Three-dimensional imaging system

A device for estimating scatter in X-ray imaging is described. An anti-scatter grid with varying grid ratio is used in conjunction with an X-ray detector. The anti-scatter grid comprises attenuating lamellae that block scattered radiation. The anti-scatter grid contains regions of lesser or greater scatter rejection efficiency, which can be achieved by variations in the grid ratio. Contrast between these regions can be used to estimate residual scatter content. A method for estimating scatter from this device is further described.

X-ray anti-scatter grid with varying grid ratio

A lens and aperture device for determining 3D information. An SLR camera has a lens and aperture that allows the SLR camera to determine defocused information.

Defocusing feature matching system to measure camera pose with interchangeable lens cameras

A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section. A plurality of attenuation elements is provided between the source and object. An actuator is connected to the attenuation elements for moving the attenuation elements. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of attenuation elements. A gantry rotates the x-ray source, the plurality of attenuation elements, and the x-ray detector around an axis of rotation.

Computed tomography system with dynamic bowtie filter

A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section. A plurality of wedges is provided between the source and object. An actuator is connected to the wedges for moving the wedges substantially perpendicular to the length of the cross-section of the collimated x-ray beam. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of wedges. A gantry rotates the x-ray source, the plurality of wedges, and the x-ray detector around an axis of rotation. A detection system measures the relative position of the plurality of wedges. The detection system comprises an optical sensor and a plurality of optical markers, where each wedge has at least one optical marker attached.

A CT apparatus for scanning an object is provided. An x-ray source is provided, wherein the x-ray source provides a collimated x-ray beam with a cross-section with a length and thickness. A plurality of wedges is provided between the source and object. An actuator is connected to the wedges for moving the wedges substantially perpendicular to the length of the cross-section of the collimated x-ray beam. An x-ray detector is located on an opposite side of the object from the x-ray source and is for detecting x-rays that pass through the object and the plurality of wedges. A gantry rotates the x-ray source, the plurality of wedges, and the x-ray detector around an axis of rotation.

A method and device for high-resolution three-dimensional (3-D) imaging which obtains camera pose using defocusing is disclosed. The device comprises a lens obstructed by a mask having two sets of apertures. The first set of apertures produces a plurality of defocused images of the object, which are used to obtain camera pose. The second set of optical filters produces a plurality of defocused images of a projected pattern of markers on the object. The images produced by the second set of apertures are differentiable from the images used to determine pose, and are used to construct a detailed 3-D image of the object. Using the known change in camera pose between captured images, the 3-D images produced can be overlaid to produce a high-resolution 3-D image of the object.

Method and device for high-resolution imaging which obtains camera pose using defocusing

A camera has a lens and aperture device for determining 3D information. A projector projects an optical pattern toward a surface. The camera has at least two off-axis apertures thereon, arranged to obtain an image of the projected pattern including defocused information. The camera is movable between different positions to image the surface from said different positions, and the projector is at a specified angle of at least 5&#xb0; relative to said camera. A processor carries out a first operation using information received through the apertures to determine a pose of said camera, and to determine three dimensional information about the object based on a degree of deformation of said optical pattern on said surface indicative of a three dimensional surface. An embodiment projects a grid of laser dots and uses laser-dot defocusing for approximate Z and thus grid correspondence, which can greatly increase the working depth of the system.

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Anaheim, CA, United States of America

Scott S Hsieh