48 results about "Calibration phantom" patented technology

The invention discloses a plane CT geometric calibration method, system, storage medium and device, and the method comprises the following steps: obtaining a plane CT to scan a calibration model body, so as to obtain a projection image of the calibration model body; the calibration die body comprises a body and a plurality of pairs of calibration small balls arranged on the body, and the plurality of pairs of calibration small balls are configured to be of a two-layer structure; wherein a sphere center connecting line of each pair of calibration small balls is perpendicular to a detector receiving plane of the plane CT; processing the obtained projection image to obtain projection coordinates of each calibration small ball; pairing the calibration balls based on the projection coordinates of each calibration ball, and determining a projection coordinate connecting line of each pair of calibration balls; determining vertical point coordinates of a radiation source focus in the plane CT in the receiving plane of the detector based on each projection coordinate connecting line; and adjusting the position of the radiation source or the detector to enable the vertical point of the radiation source to coincide with the plane center point of the detector, thereby completing calibration. The method is easy to operate, the plane CT geometric calibration precision can be effectively improved, and the calibration workload is reduced.

The present invention relates to the technical field of CT, and discloses a dual-energy-spectrum material decomposition calibration phantom and method. The dual-energy-spectrum material decomposition calibration phantom comprises an organic glass cylinder having a length of 16 cm, two Teflon cylinders having different diameters are embedded in the organic glass cylinder, and the diameters of the two Teflon cylinders are respectively one third and one fourth of the diameter of the organic glass cylinder. According to the dual-energy-spectrum material decomposition calibration phantom and method, calibration is performed on a projection, without relying on an image reconstruction process, so that energy spectrums and original projection data information can be more fully utilized, so as to obtain a more accurate image and a more accurate material decomposition result.

The invention discloses an absolute quantitative correction method and device for medical imaging equipment, and relates to the technical field of nuclear medical imaging equipment correction. When the method is executed, the actual activity concentration of the calibration die body injected with the first known tracer activity serves as the first activity concentration; then, the calibration die body injected with the first known tracer activity is collected in medical imaging equipment, and the activity concentration in a first image domain obtained through calculation serves as second activity concentration; and finally, calculating a correction factor based on the first activity concentration and the second activity concentration, wherein the correction factor is used for correcting absolute quantification of the medical imaging equipment. Therefore, the correction factor is calculated by comparing the activity concentration calculated by the medical imaging equipment with the actual activity concentration of the calibration die body, so that the medical imaging equipment can accurately adjust the measurement result according to the correction factor during subsequent absolute quantitative analysis; the effect of improving the absolute quantification accuracy of the medical imaging equipment is achieved.

The invention relates to the technical field of image processing, and discloses a CT system geometric parameter correction device and correction method.The CT system geometric parameter correction device comprises a CT system and a calibration die body, and the CT system is used for bearing a measured object or the calibration die body; the calibration die body comprises a mounting plate, an adjusting structure, a calibration structure and two identification pieces; the adjusting structure is connected to the mounting plate, the calibration structure is connected to the adjusting structure, the two identification pieces are arranged on the calibration structure, and the two identification pieces are oppositely arranged in a diagonal mode. A ray source center light beam of the CT system in an error-free state passes through the centers of the two identification pieces and the center of the detector. According to the method, the geometric parameters of the measured object at different positions can be accurately calculated, so that the calibration precision of the geometric parameters is ensured, and the quality of a reconstructed image is improved.

The present invention provides a generation method for calibration data. The calibration data is used for correction of image reconstruction of a scanning imaging device. The method comprises: placing a calibration phantom in a scanning area formed by rays, wherein the calibration phantom comprises M sections respectively composed of M materials, the M materials have M physical property theoretical values, respectively, and M is a positive integer greater than or equal to 2; by means of a detector, collecting rays passing through the scanning area so as to acquire actual projection data; on the basis of the actual projection data, using an image reconstruction algorithm to reconstruct the calibration phantom to obtain a reconstructed image; performing segmentation processing on the reconstructed image to obtain M reconstructed sub-images, wherein the M reconstructed sub-images respectively correspond to the M sections; for the M reconstructed sub-images, respectively calculating M physical property measurement values corresponding to the M sections; and generating calibration data on the basis of the M physical property theoretical values and the M physical property measurement values.

Provided are a calibration method and a calibration apparatus for an imaging device and an imaging device, which can be applied to the technical field of security checks and the field of medical diagnosis. The method comprises: calculating a first theoretical intersection line according to a theoretical position of a target point of a radiation source of the imaging device, a theoretical detection position of a detector, and a phantom position of a calibration phantom (S210); determining first detection projection information for the calibration phantom on the basis of the first theoretical intersection line, an attenuation coefficient of rays emitted by the radiation source in the calibration phantom, and ray energy spectrum distribution of the radiation source in the imaging device (S220); and adjusting a parameter of the imaging device by using difference information between the first detection projection information and second detection projection information obtained by scanning the calibration phantom with the imaging device, so as to calibrate the imaging device to obtain a calibrated target parameter (S230).

This application relates to the field of medical system coordinate system calibration technology, and provides a calibration phantom and a method for determining the pose of the calibration phantom. It allows for the calibration of image acquisition devices at different installation positions using different sets of calibration surfaces of the calibration phantom, without the need to rearrange the calibration phantom. The calibration phantom provided in this application includes multiple sets of calibration surfaces; within the same set of calibration surfaces, the first calibration surface is perpendicular to the second and third calibration surfaces respectively; the normal of the second calibration surface in the coordinate system of the image acquisition device forms a first angle with the target coordinate axis of the image acquisition device coordinate system; the normal of the third calibration surface in the coordinate system of the image acquisition device forms a second angle with the target coordinate axis; the relationship between the first and second angles is consistent across all sets of calibration surfaces.

This invention relates to a bone mineral density measurement system and method. The system includes a CT scanner with a quantitative computed tomography (QCT) module, an independent single-calibration phantom, and a QCT data image processing program. The devices can exchange data via network or mobile storage. The data receiving module of the QCT data image processing program receives medical digital images from the CT scanner and measures the patient's bone mineral density through the bone mineral density analysis module. This invention combines a CT scanner, QCT, and a single-calibration phantom, employing an asynchronous scanning method that separates the phantom and the patient. This results in higher measurement accuracy, greater convenience, and improved patient comfort.

This application relates to the field of medical imaging technology, and in particular to a method, apparatus, device, system, and medium for geometric calibration of a multi-source multi-detector system. The method includes: determining the coupling relationship between the X-ray source and detector of the multi-source multi-detector system based on the irradiation relationship between the X-ray source and detector; dividing the X-ray source and detector of the multi-source multi-detector system into coupled X-ray source subsets, coupled detector subsets, and uncoupled subsets based on the coupling relationship; designing a calibration phantom based on the design parameters of the multi-source multi-detector system and constructing a calibration dataset; and iteratively solving the geometric parameters of the multi-source multi-detector system sequentially based on the coupled X-ray source subset, coupled detector subset, uncoupled subset, and an objective function constructed using the calibration dataset, to complete the calibration of the overall geometric parameters of the multi-source multi-detector system. This solves the problem of high computational complexity in the geometric parameter calibration of multi-source multi-detector systems in related technologies.

An apparatus and method for calibrating a photon-counting computed tomography (PCCT) apparatus, includes performing for each offset from a rotation center, a scan of a calibration phantom placed at the offset to obtain calibration data including measured count rate data. Location parameters of the calibration phantom are estimated for each of the plurality of offsets, based on the obtained calibration data. Thickness data of the calibration phantom is determined based on the estimated location parameters. A curve is estimated, by curve fitting using the measured count rate data and the determined thickness data, indicating a relationship between the energy bin count rate and phantom thickness, for each energy bin of each pixel of the plurality of pixels. A first look-up table is generated for pixel-to-pixel count rate variation correction, and the first look-up table is applied to acquired energy bin count data to reduce ring artifacts in an image reconstructed using the acquired energy bin count data. A second look-up table is generated for both pixel-to-pixel count rate variation correction and additional count-rate non-linearity correction, using water as the calibration material, and the second look-up table is applied to reduce both ring artifacts and cupping or doming artifacts in an image reconstructed using the acquired energy bin count data.

A method for reducing metal artifacts in CT images, including the following steps: a material decomposition (MD) calibration step, using multiple MD calibration phantoms with known characteristics and multiple spectral CT data corresponding thereto to construct a system characteristic model of spectral CT; and a MD testing step, including: the following steps: imaging multiple testing objects with a different unknown material and thickness to obtain projection-based multiple spectral CT imaging data of different energy bins; obtaining corresponding multiple basis material images of different materials based on projection data according to the spectral CT imaging data and the system characteristic model of spectral CT; and combining the basis material images and a photon energy information to be recombined with each other to obtain multiple virtual monoenergetic images.

The invention provides a PCCT device and a control method thereof, which can improve interpolation precision related to substance discrimination and shorten processing time. This PCCT device is provided with: a scanner that rotates, around a subject, an X-ray source that irradiates X-rays to the subject and a photon counting detector that detects X-rays that have passed through the subject for each of a plurality of energy intervals; and an image generation unit that generates a tomographic image using projection data calculated from the output of the photon counting detector, the PCCT device being characterized by being further provided with: a map creation unit that creates a tomographic image using projection data calculated from the output of the photon counting detector; creating a calibration data map on the basis of the number of X-ray photons transmitted through each of a plurality of calibration phantoms having a first base material and a second base material of known material and thickness; a region division unit that divides the calibration data map into a non-linear region and a linear region; and an interpolation unit that performs a non-linear interpolation in the non-linear region and a linear interpolation in the linear region.

The application discloses a skin dose calculation method based on a depth camera, comprising the following steps: obtaining the transformation relationship between the beam coordinate system of a three-dimensional perspective device and the camera coordinate system of the depth camera by calibrating a calibration phantom with a plurality of marker balls; collecting corresponding images by the depth camera and calculating the coordinates of each pixel point in the image under the beam coordinate system according to the transformation relationship; determining the beam region according to the beam angle of the ray source, combining the coordinates of each pixel point to determine the actual incident position and the incident depth of the patient, and calculating the corresponding skin dose accordingly. The application can locate the actual incident position of the patient by the depth camera, calculate the skin dose at the actual incident position, and display accurate skin dose indication.

A calibration phantom is configured to be difficult to deform and easy to handle. The calibration phantom can be used in a case of acquiring calibration data of a photon-counting type detector that outputs an electrical signal corresponding to photon energy of an incident X-ray. The calibration phantom includes first base substances and a second base substance which are known substances, the second base substance having an atomic number larger than an atomic number of the first base substances and being sandwiched between the first base substances.

The application discloses an absolute quantitative correction method and device of a medical imaging equipment, and relates to the technical field of correction of nuclear medical imaging equipment. In the execution of the method, the actual activity concentration of a calibration phantom injected with a first known tracer activity is taken as a first activity concentration; then the activity concentration of the calibration phantom injected with the first known tracer activity in a first image domain acquired and calculated by the medical imaging equipment is taken as a second activity concentration; and finally, a correction factor is calculated based on the first activity concentration and the second activity concentration, and the correction factor is used for correcting the absolute quantification of the medical imaging equipment. In this way, the correction factor is calculated by comparing the activity concentration calculated by the medical imaging equipment with the actual activity concentration of the calibration phantom, so that the medical imaging equipment can accurately adjust the measurement results according to the correction factor when performing subsequent absolute quantitative analysis, and the effect of improving the absolute quantitative accuracy of the medical imaging equipment is achieved.

To provide a PCCT device capable of improving interpolation precision regarding material discrimination and shortening the processing time, and a control method for the device.SOLUTION: A PCCT device including an X-ray source irradiating a subject with X rays, a scanner turning a photon counting type detector that detects the X-rays passing through the subject for each of a plurality of energy bins around the subject, and an image generator using projection data calculated on the basis of an output of the photon counting type detector to generate a tomographic image is characterized by further having: a map generation unit generating a calibrated data map on the basis of the number of X-ray photons passing through each of a plurality of calibration phantoms having a first base material and a second base material with known materials and thickness; an area division unit dividing the calibrated data map into a non-linear area and a linear area; and an interpolation unit performing non-linear interpolation in the non-linear area and linear interpolation in the linear area.SELECTED DRAWING: Figure 4

The invention provides radiotherapy equipment, a calibration die body and a positioning lamp calibration method. The radiotherapy equipment comprises an annular rack, three positioning lamps and support assemblies in one-to-one correspondence with the positioning lamps. The three sets of support assemblies are arranged in the circumferential direction of the annular rack at intervals, and each positioning lamp is arranged on the corresponding support assembly and is adjustable in posture. The postures of the three positioning lamps meet the condition that one positioning lamp emits a positioning light beam corresponding to the sagittal plane of the human body, and the other two positioning lamps are oppositely arranged and respectively emit two positioning light beams which are perpendicular to each other and correspond to the cross section and the coronal plane of the human body one to one; and positioning light beams emitted by the three positioning lamps are intersected at a set virtual isocenter. According to the radiotherapy equipment, the positioning lamp is directly arranged on the annular rack of the radiotherapy equipment, so that the distance between the positioning lamp and the virtual isocenter is reduced, the moving distance of a user can be reduced in the process of debugging and calibrating the positioning lamp by the user, and the debugging and calibrating efficiency of the positioning lamp is improved.

Disclosed herein is a computer-implemented method for calibrating an imaging apparatus mounted to a rotatable gantry, wherein the imaging apparatus comprises a detector, and a source of imaging radiation configured to emit imaging radiation in a field of view, the emitted imaging radiation having an imaging radiation axis. The method comprises performing a calibration process which comprises obtaining a first projection image of a calibration phantom positioned at a first position within the field of view, determining a projected location of the calibration phantom in the first projection image, and, based on a distance between the determined projected location of the calibration phantom and one or more pixels in the first projection image representing a crossing point between the detector and the imaging radiation axis when the imaging apparatus is in a preferred configuration, determining a relative angle of rotation, α, between the detector and the source of imaging radiation.

To provide a calibration phantom holder which reduces the number of components required for calibration and an installation area, and also reduces the number of user operations of an engineer who performs calibration.SOLUTION: A calibration phantom holder for an imaging system is provided. In an example, the calibration phantom holder comprises a horizontal member comprising a plurality of parallel slots on a top surface of the horizontal member. Each parallel slot of the plurality of parallel slots is configured to support one or more calibration phantoms. The calibration phantom holder includes a vertical member perpendicularly coupled to the horizontal member. The vertical member is configured to couple to a support system of the imaging system.SELECTED DRAWING: Figure 3

The invention discloses a pose calibration method, device and equipment based on Gaussian radiation and a storage medium, and the method comprises the steps: carrying out the image collection of a target calibration motif based on target calibration equipment, and generating a target motif image sequence; and based on a pre-trained Gaussian radiation model, performing image matching on the motif images in the target motif image sequence, and performing pose calibration on the target calibration device at a collection view angle corresponding to the motif image according to an imaging pose, corresponding to the matched motif image, in the Gaussian radiation model. According to the technical scheme, the flexibility and the stability of geometric pose calibration of the calibration equipment are improved.

The invention relates to the technical field of computed tomography, in particular to a tomography imaging method and device, tomography equipment and a storage medium, and aims to realize coordinate system alignment of high-resolution and large-view imaging links in a public reconstruction space through a first projection matrix and a second projection matrix constructed on the basis of the same calibration motif. A geometric consistency basis is provided for joint reconstruction of double-source projection data; a projection matrix is fused into a reconstruction residual error minimization process, iterative reconstruction is carried out in combination with image structure regularization constraint, global geometric consistency and local detail fidelity are both considered under the condition that an external high-resolution label is not needed, and the overall image resolution and imaging quality are improved while the large-view imaging capability is maintained.

The utility model relates to a kind of laser lamp verification mould, including mould main body, level, adjusting support leg and support leg drive assembly, cross mark area is provided on mould main body upper surface and four sides, identification metal ball is provided at the center of mould main body, level is set on mould main body upper surface, four diagonal places of mould main body lower surface are provided with screw hole, adjusting support leg includes support base and rotating column, rotating column lower end is hinged with support base, rotating column outer circumferential surface is provided with external thread, external thread and screw hole are adapted, support leg drive assembly is used to drive support leg to adjust up and down, the abrasion of this mould can be avoided when leveling operation.

The invention provides a PCCT device and a control method thereof. This PCCT device is provided with: a scanner that rotates, around a subject, an X-ray source that irradiates X-rays to the subject and a photon counting detector that detects X-rays that have passed through the subject for each of a plurality of energy intervals; and an image generation unit that generates a tomographic image using projection data calculated from the output of the photon counting detector, the PCCT device being characterized by being further provided with: a map creation unit that creates a tomographic image using projection data calculated from the output of the photon counting detector; creating a calibration data map on the basis of the number of X-ray photons transmitted through each of a plurality of calibration phantoms having a first base material and a second base material of known material and thickness; an expansion unit that creates an expanded data map obtained by expanding the calibration data map to a negative region by performing extrapolation processing on the number of X-ray photons; and a substance discrimination unit that discriminates a substance on the basis of the extended data map.

The invention belongs to the field of magnetic particle imaging, particularly relates to a system function calibration method and device for magnetic particle imaging without magnetic field lines, and aims to solve the problem of poor system function effect during magnetic particle image reconstruction in the prior art. The method comprises the following steps: acquiring an empty background signal, and fixing a calibration phantom at a central position without a magnetic field line; according to the normal direction of the non-magnetic-field line, moving the non-magnetic-field line or calibrating the phantom and synchronously acquiring an original signal; according to the empty background signal and the original signal, determining an effective signal and extracting a target signal; constructing a mapping array according to the relative distance between the non-magnetic field line and the calibration phantom, performing up-sampling, and mapping to a calibration space of a system function; and calculating the relative distance of each point in the system function and pairing and filling the calibration data to obtain a calibrated system function. According to the method, the measurement and calibration of the system function can be completed only by gradually scanning the non-magnetic field line along the normal single direction, the interference is small, and the efficiency and the accuracy are higher.

The invention relates to a method for producing a calibration phantom to support diagnosis in computed tomography and an analysis method, which continuously remains inside a CT device, provides calibration in all scans by fully covering a wide spectrum of the HU scale, enables inter-device data standardisation, and has data processing methods that may be developed within this scope, thereby providing different application areas.

A calibration phantom holder for an imaging system is provided. In one example, the calibration phantom holder includes a horizontal member with a plurality of parallel slots distributed along an upper surface of the horizontal member. Each parallel slot of the plurality of parallel slots is configured to support one or more calibration phantoms. The calibration phantom holder includes a vertical member perpendicularly coupled to the horizontal member. The vertical member configured to couple to a support system of the imaging system.

The invention relates to a method and system for visualizing out-of-plane marking in ultrasonic guided intervention, and the method comprises the steps: building rigid transformation between an ultrasonic image plane coordinate system and a mechanical arm world coordinate system through a calibration phantom, and selecting a target point in a real-time ultrasonic image to obtain a three-dimensional coordinate of the target point; taking the recorded imaging plane as a reference, adopting plane constraint control to enable the probe to move in a parallel plane, and projecting the stored three-dimensional mark points to the current ultrasonic image based on the updated probe attitude to realize visual display of the out-of-plane structure; the system comprises an execution unit, a control unit, a display unit and a calibration phantom, and is used for completing space registration, mark point calculation and projection superposition. According to the invention, continuous three-dimensional positioning reference can be provided while the real-time performance of two-dimensional ultrasonic imaging is maintained, and the accuracy and operation efficiency of an interventional operation are improved.

This disclosure provides a method for obtaining an energy threshold, a method for decomposing a matrix material, a system, an apparatus, and a medium. The method for obtaining the energy threshold includes: acquiring imaging images of at least two preset calibration phantoms corresponding to preset energy ranges based on preset imaging parameters; wherein the preset calibration phantoms include a target matrix material, and the preset energy ranges are determined according to a preset energy threshold in the preset imaging parameters; acquiring the mass decay coefficient of the preset calibration phantoms based on the imaging images; determining the decay difference between the target matrix materials based on the mass decay coefficient; and determining the target energy threshold for imaging based on the decay difference and the preset energy threshold. This disclosure calculates the decay difference based on the actually measured mass decay coefficient of the preset calibration phantom corresponding to the target matrix material, and determines the target energy threshold based on the decay difference and the preset energy threshold used during measurement, which can assist in determining the selection of the target energy threshold for any target matrix material to be decomposed.

The invention relates to the technical field of CL imaging, in particular to a CL system rotating shaft projection position calculation method. The method comprises the steps that a sample is placed on an objective table, the height is adjusted to ensure complete projection capture, the objective table is controlled to rotate by a circle to collect a plurality of projection images with marked angles and coordinates at equal angle intervals, all the projections are superposed to generate a composite image, and fixed feature points form an elliptical orbit; delimiting a row coordinate interval containing effective sample projection points in the row direction of the composite image as a candidate symmetry axis search range, traversing the row position of each hypothetical symmetry axis in the range, constructing a symmetric row pair combination, and calculating the sum of pixel value differences of all row pairs under each hypothetical symmetry axis; and selecting the row coordinate with the minimum difference sum as the projection position of the rotating shaft in the Y direction of the detector. According to the method, high-precision positioning is realized through symmetry analysis of the projection superposition image, a die body does not need to be calibrated, the stability of a calculation result is remarkably superior to that of a traditional technology, and the definition of a reconstructed image is effectively improved.

The invention discloses an ultrasonic probe calibration device, and relates to the technical field of ultrasonic imaging and navigation positioning, the device adopts an ultrasonic probe calibration device matched with a calibration phantom method to calibrate an ultrasonic probe fixed with an optical marker or a magnetic sensor, so that different types of ultrasonic probes can be calibrated through matched software. The method is compatible and universal, and meets the preset navigation positioning precision. The sealed liquid storage box ensures reliable sealing of the liquid in the expected inner box, can also simply and conveniently replace the liquid in the box, and is convenient to use, environment-friendly, reliable and durable. After the liquid storage box is filled with liquid, the sealing cover can be bulged by a preset height through a flexible material, and ultrasonic probes of different shapes and types such as a rod type and a block type are used in a compatible mode.