380 results about "Computed tomographic" patented technology

A high speed computed tomography x-ray scanner using a plurality of x-ray generators. Each x-ray generator is scanned along a source path that is a segment of the scanner's source path such that each point in the source path is scanned by at least one tube. X-ray generators and detectors can be arranged in different scan planes depending on the available hardware so that a complete and near planar scan of a moving object can be assembled and reconstructed into an image of the object.

An ablation system including an image database storing a plurality of computed tomography (CT) images of a luminal network and a navigation system enabling, in combination with an endoscope and the CT images, navigation of a locatable guide and an extended working channel to a point of interest. The system further includes one or more fiducial markers, placed in proximity to the point of interest and a percutaneous microwave ablation device for applying energy to the point of interest.

A method and system for the automated detection and analysis of pulmonary nodules in computed tomographic scans which uses data from computed tomography (CT) scans taken at different times is described. The method and system includes processing CT lung images to identify structures in the images for one patient in each of a plurality of different studies and then relating the plurality of CT lung images taken from the patient in one CT study with a plurality of CT lung images taken from the same patient in at least one other different study to detect changes in structures within the CT images.

A technique is provided for forming a multi-layer radiation detector. The technique includes a charge-integrating photodetector layer provided in conjunction with a photon-counting photodetector layer. In one embodiment, a plurality of photon-counting photosensor elements are disposed adjacent to a plurality of charge-integrating photosensor elements of the respective layers. Both sets of elements are connected to readout circuitry and a data acquisition system. The detector arrangement may be used for energy discriminating computed tomography imaging and similar computed tomography systems.

The present invention provides a method for determining a geometry of a scanning volumetric computed tomographic (CT) system having a rotation axis, a rotational plane, an x-ray source and a detector. The method includes scanning a phantom having a series of spatially separated discrete markers with the scanning volumetric computed tomographic system, wherein the markers are configured on a supporting structure of the phantom so as to permit separate identification of each marker in a collection of projection images. The method further includes locating images of the markers in each projection, using the located marker images to assign marker locations to tracks, and using the assigned tracks, determining a relative alignment between the detector, the source, and the rotation axis of the scanning volumetric computed tomographic system.

A system and a method is disclosed for consistently and verifiably optimizing computed tomography (CT) radiation dose in the clinical setting. Mathematical models allow for estimation of patient size, image noise, size-specific radiation dose, and image quality targets based on digital image data and radiologists preferences. A prediction model estimates the scanner's tube current modulation and predicts image noise and size-specific radiation dose over a range of patient sizes. An optimization model calculates specific scanner settings needed to attain target image quality at the minimum radiation dose possible. An automated system processes the image and dose data according to the mathematical models and stores and displays the information, enabling verification and ongoing monitoring of consistent dose optimization.

A system and method are disclosed for computing a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient. The CT image dataset generated during the scan of the patient, and one or more parameters relating to a x-ray source are used to calculate the radiation dose delivered to the patient as a function of the CT image data set and the one or more parameters of the x-ray source. The radiation dose is generally found by calculating a primary x-ray dose distribution and scattered x-ray dose distribution from the CT image dataset and taking the sum of the primary x-ray dose distribution and scattered x-ray dose distribution.

A method of obtaining a computed tomography image of an object includes determining linear terms and non-linear beam hardening terms in a pair of line integral equations for dual-energy projection data from inserting average and difference from average attenuation terms, obtaining an initial solution of the line integral equation by setting the non-linear beam hardening terms to zero, and iteratively solving the line integral equations to obtain one line integral equations for each basis material. Attenuation by the first basis material corresponds to a photoelectric attenuation process, and attenuation by the second basis material corresponds to a Compton attenuation process. The line integral equations can be inverted by an inverse Radon procedure such as filtered backprojection to give images of each basis material. The images of each basis material can then be optionally combined to give monochromatic images, density and effective atomic number images, or photoelectric and Compton processes images.

A medical accelerator system consisting of coplanar and non-coplanar beams, on line magnetic resonance anatomic and functional imaging and cone beam computed tomographic imaging for single session image guided all field simultaneous radiation therapy and radiosurgery is provided. This system enables single session simulation, field-shaping block making, treatment planning, dose calculations and treatment of tumors. The radiation exposure time to the tumor and the normal tissue is reduced to a few seconds to less than a minute. In filed intensity modulated radiation is rendered by combined divergent and pencil beam, multiple smaller fields within a larger field, selectively varying beam's energy, dose rate and beam weight. Since all the treatment fields are treated simultaneously the dose rate at the tumor site is the sum of each of the converging beam's dose rate at depth. This super-high biological dose rate impairs the lethal and sublethal damage repair.

Systems and methods are provided for acquiring and reconstructing projection data that is mathematically complete or sufficient using a computed tomography (CT) system having stationary distributed X-ray sources and detector arrays. In one embodiment, a non-sequential activation is employed to acquire mathematically complete or sufficient projection data. In another embodiment, a distributed source is provided as a generally semicircular segment. In such an embodiment, an alternating activation scheme may be employed to allow one or more helices of image data to be acquired.

Systems and methods are provided for reconstructing projection data that is mathematically complete or sufficient acquired using a computed tomography (CT) system. In one embodiment, a set of projection data representative of a sampled portion of a cylindrical surface is provided. The set of projection data is reconstructed using a suitable cone-beam reconstruction algorithm. In another embodiment, two or more sets of spatially interleaved helical projection data are processed using helical interpolation. The helically interpolated set of projection data is reconstructed using a two-dimensional axial reconstruction algorithm or a three-dimensional reconstruction algorithm.

Systems and methods are provided for acquiring and reconstructing projection data that is mathematically complete or sufficient using a computed tomography (CT) system having stationary distributed X-ray sources and detector arrays. In one embodiment, a distributed source is provided as arcuate segments offset in the X-Y plane and along the Z-axis.

A method and computer-readable medium for reducing artifacts in image data generated by a computed tomography system is provided. The artifacts are due to the presence of a high density object in a subject of interest. The method comprises receiving measured sinogram data from the computed tomography system. The sinogram data is representative of sinogram elements. The measured sinogram data is reconstructed to generate initial reconstructed image data. Then corrected sinogram data is generated using the measured sinogram data. The corrected sinogram data is iteratively reconstructed to generate an improved reconstructed image data based on a weight measure derived from the measured sinogram data.

A device (1) for computer tomography, which is set up for x-ray scatter correction, features an evaluation unit (17) which evaluates values stored as a table in a data memory for x-ray scatter correction, which have been determined in advance with the aid of a Monte Carlo simulation which take account of interactions of the photons with the object (2) to be investigated.

A method for iteratively reconstructing image data acquired by a computed tomography system is provided. The method comprises generating a calculated sinogram from an image estimate and generating an error sinogram based on the calculated sinogram and a measured sinogram. Then, one or more backprojections are performed, each based upon a reconstruction parameter. The reconstruction parameter impacts at least one of convergence speed and computational cost of each iterative step and corresponding reconstruction. A filtering step is performed prior to performing the one or more backprojections. Finally, the initial image is updated by adding corresponding results of the one or more backprojections to the image estimate to obtain the reconstructed image.

A multi-modality diagnostic imaging system includes a first imaging subsystem, such as a computed tomographic (CT) system, for performing a first imaging procedure on a subject. The first imaging system has a gantry that slides along rails. A second imaging subsystem, such as a nuclear medicine system (NUC), performs a second imaging procedure on a subject. The second imaging subsystem is separate from the first imaging system, but in the same room. The second imaging subsystem has a gantry or is gantryless. A patient couch supports a subject. The patient couch is supported on a couch support having vertical adjustment and horizontally fixed. In this manner, the patient is maintained in the same position for multiple types of scans using the same couch support without horizontal translation of the patient couch and patient.

A method for reducing mis-registration during multiple energy scanning on computed tomographic (CT) imaging systems or multiple energy electron beam tomographic (EBT) systems includes scanning a portion of a patient including a cyclically moving body part using a multiple energy computed tomographic (CT) imaging system or multiple energy electron beam tomographic (EBT) system having at least two different energies, monitoring the cyclically moving body part, and gating the multiple energy CT imaging system or multiple energy EBT system in accordance with the monitored cyclically moving body part so that acquisitions are acquired at at least two different kVps. The data acquired at the different kVps are then utilized to generate material decomposition images of the cyclically moving body part.

Disclosed are methods for reconstructing a three-dimensional image of an object's volume of interest using computed tomography that employs conical-beam, intensity-modulated projections of this object. In one embodiment, a plurality of collimating devices serves to modulate the aperture of the radiation source thereby acting to modulate the intensity of the source upon the object. Also provided are image processing devices, examination apparatus, as well as a computer-readable medium and a program element adapted and configured to perform aspects of the methods disclosed herein.

A method for estimating a petrophysical parameter from a rock sample includes making a three dimensional tomographic image of the sample of the material. The image is segmented into pixels each representing pore space or rock grain. Porosity of the sample is determined from the segmented image. An image of at least one fracture is introduced into the segmented image to generate a fractured image. The porosity of the fractured image is determined. At least one petrophysical parameter related to the pore-space geometry is estimated from the fractured image.

A method, system and computer-readable medium of filtering noise pixels and other extraneous data, including saturated fat tissue and air data in image data is provided. Examples of image data may include but are not limited to magnetic resonance imaging data and computed tomography data. The method includes receiving pixel count for each signal intensity value of the image data; determining a signal intensity value, I_peak, corresponding to a pixel count of a greatest number of pixels, N_peak; setting a noise threshold at a signal intensity value, I_noise, corresponding to a pixel count, N_I, such that N_I, is determined based on N_peak; and filtering from the image data one or more pixels with signal intensity values below the noise threshold. N_I, may be determined such that N_I=N_peak/3 or close to N_peak/3.

A radiotherapeutic device has a radiotherapeutic irradiation unit with a radiation source for generation of radiotherapeutic radiation and a beam guidance and/or beam shaping device in order to direct the radiotherapeutic radiation in a defined manner onto a specific irradiation region. The radiotherapeutic device additionally has an imaging unit that includes a radionuclide emission tomography acquisition unit and a computed tomography scanner. The radiotherapeutic device also has a support device with a positioning device in order to position the support device in an image acquisition position in which a body region to be irradiated of a patient borne on or in the support device is located in an acquisition region of the image acquisition unit, or in order to position the support device in an irradiation position in which the body region to be irradiated of the patient is at least partially located in congruence with the irradiation region of the irradiation unit. The radiotherapeutic device additionally has a coordinate registration device that registers changes of all position coordinates of the support device given a movement of the support device between the image acquisition position and the irradiation position.

In one embodiment, a scanning unit for inspecting cargo conveyances uses a partial radiation beam and a detector of reduced length. In another embodiment, a scanning unit for inspecting objects comprises a detector with gaps along its expanse. In both cases, the cost of the scanning system may be reduced. The object, the source, and or the detector may be moved to enable generation of computed tomographic images. Methods are disclosed, as well.

An X-ray computed tomographic apparatus includes a gantry 100 including an X-ray tube 101 which generates X-rays and an X-ray detector 103 which detects X-rays transmitted through a subject to be examined, a reconstruction device 114 which generates tomogram data on the basis of an output from the X-ray detector, a breath detector 203 which detects a respiration waveform representing a temporal change in respiration index value associated with the subject, a regular respiration waveform generating unit 207 which generates a respiration waveform with a regular respiration cycle which originates from the detected respiration waveform, and a gantry mount display 201 which displays the generated regular respiration waveform.