82 results about "Tomographic image reconstruction" patented technology

A system for optical imaging of a thick specimen that permits rapid acquisition of data necessary for tomographic reconstruction of the three-dimensional (3D) image. One method involves the scanning of the focal plane of an imaging system and integrating the range of focal planes onto a detector. The focal plane of an optical imaging system is scanned along the axis perpendicular to said plane through the thickness of a specimen during a single detector exposure. Secondly, methods for reducing light scatter when using illumination point sources are presented. Both approaches yield shadowgrams. This process is repeated from multiple perspectives, either in series using a single illumination / detection subsystem, or in parallel using several illumination / detection subsystems. A set of pseudo-projections is generated, which are input to a three dimensional tomographic image reconstruction algorithm.

Tomographic / tomosynthetic image reconstruction systems and methods in the framework of machine learning, such as deep learning, are provided. A machine learning algorithm can be used to obtain an improved tomographic image from raw data, processed data, or a preliminarily reconstructed intermediate image for biomedical imaging or any other imaging purpose. In certain cases, a single, conventional, non-deep-learning algorithm can be used on raw imaging data to obtain an initial image, and then a deep learning algorithm can be used on the initial image to obtain a final reconstructed image. All machine learning methods and systems for tomographic image reconstruction are covered, except for use of a single shallow network (three layers or less) for image reconstruction.

A system and method for tomographic image reconstruction using truncated limited-angle projection data that allows exact interior reconstruction (interior tomography) of a region of interest (ROI) based on the linear attenuation coefficient distribution of a subregion within the ROI, thereby improving image quality while reducing radiation dosage. In addition, the method includes parallel interior tomography using multiple sources beamed at multiple angles through an ROI and that enables higher temporal resolution.

Tomography by emission of positrons (pet) system dedicated to examinations of human body parts such as the breast, axilla, head, neck, liver, heart, lungs, prostate region and other body extremities which is composed of at least two detecting plates (detector heads) with dimensions that are optimized for the breast, axilla region, brain and prostrate region or other extremities; motorized mechanical means to allow the movement of the plates under manual or computer control, making it possible to collect data in several orientations as needed for tomographic image reconstruction; an electronics system composed by a front-end electronics system, located physically on the detector heads, and a trigger and data acquisition system located off-detector in an electronic crate; a data acquisition and control software; and an image reconstruction and analysis software that allows reconstructing, visualizing and analyzing the data produced during the examination.

A system and method for tomographic image reconstruction using truncated limited-angle projection data that allows exact interior reconstruction (interior tomography) of a region of interest (ROI) based on the linear attenuation coefficient distribution of a subregion within the ROI, thereby improving image quality while reducing radiation dosage. In addition, the method includes parallel interior tomography using multiple sources beamed at multiple angles through an ROI and that enables higher temporal resolution.

The invention provides a computer tomography (CT) parallel reconstructing system and an imaging method thereof. The CT parallel reconstructing system comprises a front end sampler, a central node and a plurality of sub-nodes connected with the central node, wherein each sub-node is provided with an image processor. The imaging method of the CT parallel reconstructing system comprises the following steps: (1) a reconstructed image is divided into a plurality of block regions; (2) original projection data of each angle, which is sampled by the front end sampler, is received by the central node; (3) calculation tasks are allotted to the sub-nodes by the central node, and the reconstruction values of one or a plurality of block regions are calculated by the sub-nodes to which the reconstruction calculation tasks are allotted; (4) the reconstruction calculation tasks are completed by the sub-nodes; and (5) a complete reconstruction image is combined by the central node. By adopting the method of dividing the reconstructed image into subregions, the invention fully excavates the parallel characteristics of CT scan and reconstruction, and performs parallel reconstruction of GPU while data collection, and the reconstruction time is lowered from the minute grade of the prior art to millisecond grade, thereby accurately displaying the reconstruction of the sectional image of a detected object in real time.

A tomographic image reconstruction method produces either 2D or 3D images from fan beam or cone beam projection data by filtering the backprojection image of differentiated projection data. The reconstruction is mathematically exact if sufficient projection data is acquired. A cone beam embodiment and both a symmetric and asymmetric fan beam embodiment are described.

The invention discloses a cloud virtual machine control system and method of a CT device, and belongs to the technical field of medical treatment. The system comprises a local server with a medical image data collection module, a medical image data synchronous service module, a local checking network module and a medical image data remote transmission module, and a cloud server with a cloud computing management platform, a medical image data processing module and a remote monitoring network module. Original medical image projection data of the CT device is collected; defective pixels and offset are corrected; integrity checking is carried out on processed medical image data; the medical image data after the integrity checking is written in the medical image data synchronous service module and is transmitted to the cloud server and a doctor local control end by the medical image data remote transmission module, for doctors to carry out local data monitoring; preprocessing, cross-sectional image reconstruction, postprocessing and three-dimensional reconstruction are carried out on the medical image data in the cloud server. According to the system and the method, the space is saved, and the expenses are reduced.

In a tomographical image reconstruction method and apparatus to generate an image of an examination subject from a number of digital projection data acquired at different projection angles, a first analytical filter kernel (formed by a first analytical function) is determined for a filtered back projection in the spatial frequency range, this first analytical filter kernel approximating, at least in a range of the spatial frequency, a discrete filter kernel iteratively determined for a model. Back projection is implemented with a second analytical filter kernel calculated from the analytical filter kernel and formed by a second analytical function.

A generalized projection-slice theorem for divergent beam projections is disclosed. The theorem results in a method for processing the Fourier transform of the divergent beam projections at each view acquired by a CT system to the Fourier transform of the object function. Using this method, an inverse Fourier transform may be used to reconstruct tomographic images from the acquired divergent beam projections.

A tomographic image reconstruction method produces either 2D or 3D images from fan beam or cone beam projection data by filtering the backprojection image of differentiated projection data. The reconstruction is mathematically exact if sufficient projection data is acquired. A cone beam embodiment and both a symmetric and asymmetric fan beam embodiment are described.

The present invention relates to a method for tracking motion phase of an object. A plurality of projection data indicative of a cross-sectional image of the object is received. The projection data are processed for determining motion projection data of the object indicative of motion of the object based on the attenuation along at least a same line through the object at different time instances. A motion phase of the object with the object having the least motion is selected. Finally, projection data acquired at time instances within the selected motion phase of the object are selected for tomographical image reconstruction. Reconstructed images clearly show a substantial improvement in image quality by successfully removing motion artifacts using the method for tracking motion phase of an object according to the invention. The method is highly beneficial in cardiac imaging using X-ray CT scan.

The invention provides a mammary gland tomographic image reconstruction method and a mammary gland tomographic image reconstruction device. The mammary gland tomographic image reconstruction method comprises the steps of: initializing mechanical coordinates of mammary gland tomographic equipment and image parameters of a projected image; preprocessing the projected image; carrying out filtered back-projection on the projected image after preprocessing to generate a mammary gland 3D tomographic reconstructed image; removing detector edge artifacts in the mammary gland 3D tomographic reconstructed image; removing mammary gland edge artifacts in the mammary gland 3D tomographic reconstructed image; and removing sawtooth artifacts in the mammary gland 3D tomographic reconstructed image. The mammary gland tomographic image reconstruction method and the mammary gland tomographic image reconstruction device can be adapt to the mammary gland tomographic equipment with multiple ray sources.

Methods and systems for reconstructing an image are provided. The method includes performing a tomographic image reconstruction using a joint estimation of at least one of a gain parameter and an offset parameter, and an estimation of the reconstructed image.

A computed tomography (CT) imaging system for improving the image quality of a tomographic image at a predefined image production position in a subject's axis direction in tomographic image reconstruction by axial scanning. The CT system includes an X-ray tube and a detector array configured to conduct a plurality of scans for detecting X-rays passing through a region to be examined around an axis AX of the region to be examined at different positions along the subject's axis Ax direction; and for each of the plurality of scans, and a reconstructing section configured to calculate and reconstruct data for tomographic images of the region to be examined at a position corresponding to a detector row in the axis direction based on detected data acquired in that scan, and combine the data for the plurality of reconstructed tomographic images to generate data for a combined tomographic image at the position corresponding to the detector row.

Methods and systems for reconstructing an image are provided. The method includes performing a tomographic image reconstruction using a joint estimation of at least one of a gain parameter and an offset parameter, and an estimation of the reconstructed image.

The invention provides equipment and a method for dental X-ray tomography, wherein the equipment comprises a scanning control module, an X-ray machine, a mechanical scanner, an image acquisition control module, an X-ray detector and a tomographic image reconstruction module as well as an image display module, wherein the scanning control module is used for emitting an exposure pulse signal to control the exposure of the X-ray machine and emitting an acquisition pulse signal to control the acquisition work of the image acquisition control module; the mechanical scanner is used for driving the X-ray machine to move to different positions to finish the tomographic scanning process; the image acquisition control module is used for converting, digitalizing and transmitting detection results of the X-ray detector; the tomographic image reconstruction module is used for reconstructing an acquired multi-angle X-ray perspective image to obtain a multi-position cross-sectional image of a tissue to be imaged; the position to be imaged is arranged between the X-ray machine and the X-ray detector, and X rays emitted by the X-ray machine always pass through the X-ray detector. The equipment for dental X-ray tomography, provided by the invention, has the advantages of low cost, high imaging speed and good imaging effect.

Algorithms are disclosed that recombine acquired data so as to generate a substantially uniform and complete set of frequency data where frequency data might otherwise be incomplete. This process, or its equivalent, may be accomplished in a computationally efficient manner using filtering steps in one or both of the reconstruction space and / or the post-processing space.

The invention discloses a CT digital subtraction angiography (CT / DSA) imaging system and CT digital subtraction angiography (CT / DSA) imaging method. The CT / DSA imaging system is composed of an x-ray generator, an energy resolution photon counting detector, a CT image reconstruction unit, a digital image subtraction unit, an image storage, transmission and display unit, an examining bed, a machine frame and a controller, wherein an x-ray source generates continuous energy spectrum x rays for fast scanning the human body; the energy resolution photon counting detector is used for detecting the x photons penetrating through the human body and judging and counting the energy of the x photons; the CT image reconstruction unit is used for collecting signals output by the energy resolution photon counting detector, so that two groups of transmission projection data of a high-energy area and a low-energy area are formed, and the projection data of the high-energy area and the projection data of the low-energy area are subjected to tomography image reconstruction by adopting an analytical reconstruction algorithm or a statistical reconstruction algorithm; the digital image subtraction unit is used for applying different weights to the tomography reconstruction images of the high-energy area and the low-energy area of each same scanning position and carrying out subtraction calculation, and thus the CT digital subtraction angiography image is obtained.

Tomography by emission of positrons (pet) system dedicated to examinations of human body parts such as the breast, axilla, head, neck, liver, heart, lungs, prostate region and other body extremities which is composed of at least two detecting plates (detector heads) with dimensions that are optimized for the breast, axilla region, brain and prostrate region or other extremities; motorized mechanical means to allow the movement of the plates under manual or computer control, making it possible to collect data in several orientations as needed for tomographic image reconstruction; an electronics system composed by a front-end electronics system, located physically on the detector heads, and a trigger and data acquisition system located off-detector in an electronic crate; a data acquisition and control software; and an image reconstruction and analysis software that allows reconstructing, visualizing and analyzing the data produced during the examination.

In a tomographical image reconstruction method and apparatus to generate an image of an examination subject from a number of digital projection data acquired at different projection angles, a first analytical filter kernel (formed by a first analytical function) is determined for a filtered back projection in the spatial frequency range, this first analytical filter kernel approximating, at least in a range of the spatial frequency, a discrete filter kernel iteratively determined for a model. Back projection is implemented with a second analytical filter kernel calculated from the analytical filter kernel and formed by a second analytical function.

A tomographic image capturing apparatus comprises a radiation source for applying radiation to a subject at a plurality of different angles with respect to the subject, a radiation detector for detecting the radiation which has passed through the subject at each of the different angles and converting the detected radiation into image data, a tomographic image reconstructing unit for processing the image data into a reconstructed tomographic image, and an image capturing continuation determining unit for determining whether image-capturing of the subject is continued or not based on the reconstructed tomographic image.

A method of performing a computed tomographic image reconstruction is provided. The method provides for performing a short scan of an imaging object to acquire a short scan data, performing a plurality of image reconstructions based on the short scan data wherein the plurality of image reconstructions result in a corresponding plurality of image volumes wherein the image reconstructions use different view weighting functions, filtering the plurality of image volumes such that when the volumes are added together, the frequency domain data is substantially uniformly weighted. Further, the method provides for combining the plurality of image volumes together to produce a final image volume.

A tomography system includes a radiation source, a radiation detector, a subject table, an imaging unit and a reconstruction unit. The imaging unit obtains a projection image a predetermined number of times while changing a positional relationship of the radiation source and the radiation detector. The reconstruction unit generates a tomogram of a subject using the projection image obtained by the imaging unit. The reconstruction unit includes a correction unit. The correction unit performs correction processing to (i) create a profile of a pixel signal value from a no-subject-included projection image obtained by the imaging unit without the subject on the subject table and (ii) correct, on the basis of the created profile, a subject-included projection image obtained by the imaging unit with the subject on the subject table or a detection probability used in generating the tomogram.

The invention discloses a bone fault image reconstruction method and system. The method comprises the following steps of S1, obtaining a three-dimensional bone CT image template; S2, generating a local two-dimensional bone gamma plain film image template; S3, matching the whole body bone gamma plain film image to obtain the most matched local two-dimensional bone gamma plain film image; S4, further optimizing the three-dimensional bone CT image template, and enabling the two-dimensional bone gamma image template corresponding to the three-dimensional bone CT image template to completely cover the region of interest of the local bone gamma image; s5, reconstructing a quantitative local bone gamma tomography image based on the template; and S6, carrying out fusion display on the local bone gamma tomography image and the CT tomography image. By means of the method and system, the level close to the quality of a tomographic image obtained through conventional SPECT tomographic acquisition and reconstruction can be achieved after fusion, a doctor can analyze and diagnose the tomographic image more visually, clinical examination is conducted on part of patients, extra tomographic acquisition is avoided, and efficiency is improved.

An X-ray tube (X-ray focus) and an X-ray detector opposed to each other across an object synchronously scan the object to acquire radiographic data in each scan position. A section reconstruction method is provided in which the radiographic data or data resulting from a filtering process of the radiographic data is projected as back projection data back to a two-dimensional or three-dimensional reconstruction area virtually set to a region of interest of the object. Enlarged interpolation data is generated by interpolating the back projection data and then the enlarged interpolation data is projected back to the reconstruction area without interpolation. The number of interpolation computations is reduced to an amount corresponding to the enlargement by interpolation of the back projection data, to shorten the reconstruction computation time.