147 results about "Three dimensional ct" patented technology

A tiny electrically powered hydrodynamic blood pump is disclosed which occupies one third of the aortic or pulmonary valve position, and pumps directly from the left ventricle to the aorta or from the right ventricle to the pulmonary artery. The device is configured to exactly match or approximate the space of one leaflet and sinus of valsalva, with part of the device supported in the outflow tract of the ventricular cavity adjacent to the valve. In the configuration used, two leaflets of the natural tri-leaflet valve remain functional and the pump resides where the third leaflet had been. When implanted, the outer surface of the device includes two faces against which the two valve leaflets seal when closed. To obtain the best valve function, the shape of these faces may be custom fabricated to match the individual patient's valve geometry based on high resolution three dimensional CT or MRI images. Another embodiment of the invention discloses a combined two leaflet tissue valve with the miniature blood pump supported in the position usually occupied by the third leaflet. Either stented or un-stented tissue valves may be used. This structure preserves two thirds of the valve annulus area for ejection of blood by the natural ventricle, with excellent washing of the aortic root and interface of the blood pump to the heart. In the aortic position, the blood pump is positioned in the non-coronary cusp. A major advantage of the transvalvular VAD is the elimination of both the inflow and outflow cannulae usually required with heart assist devices.

A method for correcting inherent distortions in a CT or MRI imaging process, or distortions arising from excessive patient movement during the scan by means of a registration device inserted into the mouth of the patient at the time the scan is being performed. The registration device incorporates a set of fiducial markers disposed in a predetermined three-dimensional pattern. The exact positions of the fiducial markers are known with respect to each other, thus providing a three-dimensional reference against which the resulting images can be compared. Additionally, a method whereby three-dimensional CT or MRI images taken prior to an operation, are accurately registered and integrated with real-time tracking positional data of the patient's body part and instruments operating thereon. Application is described for the drilling of a patient's jaw for the placement of dental implants.

The invention relates to a method for remodeling a three-dimensional pore structure of a core. The method comprises the following steps of carrying out high-resolution three-dimensional micro-CT (Captive Test) on a full diameter core so as to generate full diameter core CT data; selecting a core matrix from the full diameter core to carry out a higher-resolution three-dimensional micro-CT or a casting sheet experiment so as to obtain the information of a pore structure of the matrix; obtaining a secondary three-dimensional pore structure through three-dimensional CT remodeling by utilizing the full diameter core CT data; obtaining the three-dimensional pore structure of the matrix through the three-dimensional CT remodeling by utilizing the obtained information of the pore structure of the matrix or through geological statistics remodeling by utilizing sheet images; integrating the three-dimensional pore structure of the full diameter core with the three-dimensional pore structure of the matrix so as to obtain a three-dimensional fine pore structure of the core, which is provided with both secondary pore characteristics and matrix pore characteristics; and obtaining parameters of pore structures with different dimensions of the core and parameters of connectivity of three-dimensional space according to the three-dimensional fine pore structure of the core.

A system and method provide for more accurate SPECT/CT image registration. CT data is utilized to establish a global spatial coordinate system of a common test phantom. The common test phantom is then used to obtain a set of point source nuclear images. Three-dimensional CT point source data is mapped to a two-dimensional image plane of corresponding point source data, to obtain a pair of intersecting projection cones that are used to obtain a set of detector head position correction parameters to correct detector head positioning in the CT coordinate system when obtaining SPECT projection images of the same object.

In an X-ray CT device, the scan conditions of the device are set, a three-dimensional X-ray passage length model of the body being examined is generated from a scanogram image of the body, the control pattern of the tube current is automatically set on the basis of the scan conditions and the three-dimensional passage length model, and the dose which will be given will be calculated and displayed on the basis of the control pattern of the tube current, and three-dimensional CT value model data of the body generated on the basis of a standard human body. The scanogram image of the body and the control pattern of the tube current are displayed next to each other or overlap to allow an operator to edit the control pattern while viewing the body, so that a suitable tube current can be set.

The invention discloses a CT image liver segmentation method and system based on an automatic context model and capable of increasing liver segmentation precision in a CT image. The method comprises steps of: reading a training image set and a to-be-segmented image; extracting the textural feature of each pixel in the images; classifying the feature of each pixel in the to-be-segmented image by using a classifier to obtain an initial liver probability graph; extracting the context feature of each pixel in the images; combining the context features with the textural features and learning a series of classifiers by means of iteration until convergence to obtain a liver probability graph; using the liver probability graph as prior information and adding the liver probability graph a prior constraint condition to a randomly walking objective function as to obtain a random walk model based on context constraint for segmenting the liver; achieving liver segmentation of a three-dimensional CT image layer by layer on a two-dimensional slice of the to-be-segmented image, and interpolation and complement of a liver bound discontinuous area so as to obtain a smooth continuous liver surface.

The invention provides a two-dimensional and three-dimensional medical image registration method, which can quickly carry out registration on an intra-operative two-dimensional X-ray image and a preoperative three-dimensional CT (Computed Tomography) image. The two-dimensional and three-dimensional medical image registration method comprises the following steps: carrying out filtering preprocessing on the three-dimensional CT image, projecting the three-dimensional CT image in two mutually-orthogonal plane systems to obtain two corresponding digitally reconstructed radiograph (DRR) sets according to a maximum intensity projection (MIP) algorithm; obtaining two two-dimensional X-ray images on another two orthogonal planes, and carrying out the filtering preprocessing on the two-dimensional X-ray image; carrying out traversal on the two DRR sets, and carrying out registration on the two DRR sets and another two orthogonal two-dimensional X-ray images so as to determine a corresponding most similar DRR as well as the in-plane position coordinate, the in-plane rotation angle and an out-of-plane rotation angle of the DRR; converting the coordinate and the angles to be under a three-dimensional CT image coordinate system to obtain six registration parameters. According to the method, the X-ray image and the CT image which is generated in advance can be subjected to accurate and quick real-time registration.

The 3D CT imaging method for large view field comprises: (1) taking first single-circular orbit cone-beam CT scanning to obtain the first digital ray projection image sequence; (2) removing the platform vertical the main ray with some distance to take the second CT scanning and obtain the second image sequence; (3) correcting former two images for dark current and inconsistency; (4) recording distance from ray source to detector, former moved distance and detector level channel number; (5) with the projection rearrangement algorithm in this invention, rearranging former two images into self-contained quasi-parallel image sequence; (6) with the quasi-parallel ray reconstructing algorithm in this invention, reconstructing the 3D CT image. This invention can enlarge the view area more than 3 times with high efficiency.

The invention relates to a surgical navigation simulation method based on an electromagnetic positioning technology and intraoperative image guidance. The surgical navigation simulation method comprises the steps that 1, a preoperatively shot CT image of a patient is obtained; 2, the preoperatively shot CT image of the patient is reconstructed into a three-dimensional CT model; 3, registration andvisualization of surgical instruments are achieved; 4, the electromagnetic positioning technology is utilized to achieve real-time tracing of the surgical instruments under an image coordinate system; 5, an ultrasonic probe is calibrated, an ultrasonic image is obtained during operation in real time, and preliminary fusion between the three-dimensional CT model and the ultrasonic image is achieved; 6, by utilizing grey information and characteristic information of the ultrasonic image and adopting a mutual information method and an automatic SIFT characteristic extraction method, real-time registering of the preoperative three-dimensional CT model and the intraoperative ultrasonic image in the surgical process is performed; 7, simulation control of surgical robot movements is achieved. Compared with the prior art, the surgical navigation simulation method has the advantages of high navigation precision, low calculation complexity, good stability and reliability, convenient achievement, low cost, good clinic applicability and the like.

The present invention discloses a method and an apparatus for automatically identifying a region of interest in a three-dimensional CT image. The method includes: training a 3D convolution neural network through a three-dimensional CT image marked with a region of interest to obtain a 3D convolutional neural network with a high identification rate for the region of interest; then, through the trained 3D convolution neural network, identifying the obtained three-dimensional CT image and obtaining the region of interest; and calculating the volume, the expansion direction and the expansion diameter of the interest of interest. With the method of the embodiments in the invention, the region of interest representing the lesion can be obtained automatically and efficiently, and the identifying accuracy is also higher. In addition, the volume, the expansion direction and the expansion diameter of the lesion can be automatically calculated, therefore, helping the doctor to make a more accurate judgment of the condition of a patient.

A non-rigid registering method of a mouse three-dimensional CT image comprises the following steps: A, a direction and a position of a source image of a mouse three-dimensional CT image are calibrated; B, a threshold segmentation algorithm is used to segment the mouse image to obtain a mouse bone of the source image and a mouse bone of a target image, a center of mass of a bone slice connected domain is extracted to serve as a characteristic point, so that a source image characteristic point and a target image characteristic point are obtained; C, the source image characteristic point and the target image characteristic point in the step B are matched, the matched characteristic point is used to calculate a thin plate batten transformation matrix, and a hierarchical transformation mode is used to carry out the thin plate batten transformation to the mouse source image; and D, the mouse source image after the thin plate batten transformation and the target image carry out a fine registering. According to the invention, when the characteristic points are extracted, the number of characteristic points is reduced; the hierarchical transformation mode is used to overcome the defect of long registering time; an automatic registering in the image registering is basically realized; and registering the three-dimensional mouse image is easier.

The invention discloses a method for online detecting an electronic element by a translational type micro focus CT (Computerized Tomography) detection device, and the method is realized as follows: when the detection is started, the electronic element is scanned by a conical ray beam generated by a ray generation device; and ray projection data is acquired by a ray detection and data acquisition device, and then is transmitted to a control and image processing system for imaging including digital radiation (DR) imaging and computerized tomography (CT) imaging. When the CT imaging is performed, the CT image can be reconstructed according to incomplete projection data acquired through ray scanning by the translational type conical beam and adopting translational type conical beam CT iterative reconstruction algorithm based on subdomain equalization and total variation minimization, so as to obtain a high quality three-dimensioanl CT image. The method is used for online detecting the electronic element on the production line with high precision, can perform amplification DR image and three-dimensional CT image for internal and external structures of the electronic element; the device has simple structure and high scanning efficiency; and further, material deficiency and assembly deficiency of the electronic element can be detected efficiently.

The invention discloses a system for capturing and visualizing mandibular three-dimensional motion. The system comprises a mandibular motion tracking device for designing and printing through a three-dimensional CT (Computed Tomography) model, at least two infrared cameras, and a host computer for analyzing shooting record data, wherein the mandibular motion tracking device comprises a rear end fixing device, a medium connecting rod, and three marking rods, wherein the three marking rods are arranged at the front end and are not co-planar; one end of each of the marking rods is connected to the medium connecting rod and while the other end of each of the marking rods is provided with a marker; the rear end fixing device is used for designing and printing through the three-dimensional CT model according to the external physical characteristics of lower teeth; the markers expose from the mouth and move together with the mandible; the host computer is used for recovering the overall motion of the mandible of a tested subject so as to determine whether the mandible motion and occlusal contacts are normal. The invention also provides a method for capturing and visualizing the mandibular three-dimensional motion. According to the technical scheme, the system and method have the advantages of low cost, high testing accuracy and the like, and is convenient to operate.

The invention is applicable to the field of image processing and provides an estimation method and system for a lung motion model. The method includes: extracting a control point in a lung three-dimensional CT image of a reference phase; using a tracking position at a previous moment of the control point as a prediction position and tracking the position of the control point in a continuous-discrete-phase three-dimensional CT image; performing least-square curve fitting on the continuous-discrete-phase pursuit path of the control point and determining the motion position of the control point at any continuous time; and constructing a three-dimensional deformation model of the lung at a current time according to the motion position of the control point at any continuous time and obtaining lung motion position estimation of any voxel of the lung of the reference phase at any time. The estimation method and system for the lung motion model adopts an image registration algorithm based on a mark point so that the method is small in calculation quantity, high in calculation speed and capable of estimating the motion model of the lung effectively.

The present invention discloses a three-dimensional core image super-resolution reconstruction method. The method comprises the steps of: performing degradation on a three-dimensional CT core image, and performing decomposition and feature extraction on the degraded three-dimensional image to obtain a feature block 2; performing dictionary training on an extraction feature application algorithm to obtain a low-resolution dictionary Dl and a sparse coefficient alpha; performing decomposition and feature extraction on the input three-dimensional image to obtain a feature block 1; according to the feature block 1 and the sparse coefficient alpha, obtaining a high-resolution dictionary Dh of the input three-dimensional CT core image; according to the feature block 1 and the low resolution dictionary Dl, obtaining a new sparse coefficient beta; according to the high-resolution dictionary Dh and the new sparse coefficient beta, obtaining a three-dimensional high-resolution image block; performing up-sampling on the three-dimensional CT core image by using an interpolation algorithm and obtaining an enlarged three-dimensional image; and filling the enlarged three-dimensional image with the three-dimensional high-resolution image blocks to obtain an enlarged three-dimensional core sample model. According to the three-dimensional core image super-resolution reconstruction method, the problem of a contradiction between the resolution of the three-dimensional CT image and the sample dimension is solved.

The invention discloses a method for preparing an acetabulum side model and a guide plate based on a three-dimensional reconstruction technology. The method comprises the following steps: firstly, establishing a digital three-dimensional data model after three-dimensional CT (Computed Tomography) data of a preoperative hip joint of a patient is processed, reconstructing a three-dimensional bony structure of an acetabulum side, and restoring an original state of a disease; secondly, making an acetabulum mill filing and acetabulum screw embedding scheme by analyzing an acetabulum position, estimating an acetabulum state, clearing the mass of bones around an acetabulum and calculating the thickness of the bones around the acetabulum, and performing three-dimensional modelling on the guide plate and the model; thirdly, preparing a preoperative acetabulum side osseous model, an intra-operative grinding mortar guide plate, an intra-operative acetabulum screw guide plate and a postoperative acetabulum side osseous model by utilizing a 3D (Three-dimensional) printer; fourthly, integrating and inspecting the guide plate and the model, redesigning if the guide plate and the model are unqualified, and disinfecting the guide plate and the model and putting the guide plate and the model into an operation if the guide plate and the model are qualified.

The invention relates to a segmentation method of medical images, and specifically relates to a segmentation method of viscera and internal blood vessels thereof in a surgical planning system. The method designs a segmentation method of images of liver parenchyma, portal veins and hepatic veins based on minimal supervised classification of the three-dimensional CT images of the viscera and internal tubular tissues thereof. The method applies methods of statistics and spatial information, introduces high credible points, and obtains segmentation results based on arrival time of fast march of grey level. The method assumes that spatially adjacent points belong to a same organ, and performs segmentation calculation on the images by using a classification algorithm based on the above assumption, wherein the segmentation calculation comprises the steps of: acquiring estimated values of parameters of a Gaussian mixture distribution model; selecting the high credible points; and calculating the mean value of the grey level of the images and calculating the arrival time by using a fast marching algorithm to obtain arrival time images of three tissue classifications. According to the invention, good robustness and good anti-noise interference capability are obtained, accumulated errors are eliminated effectively, classification accuracy is improved, and great application value in clinical treatment is achieved.

The invention provides a method and system for partitioning a construction in a CT image. The method includes the steps that the opacity of the CT image is adjusted, and a construction structure in the CT image is obtained; the construction to be partitioned is determined in the obtained construction structure, interactive partition is conducted on one layer of the CT image of the construction to be partitioned, the processes are that firstly, the gradient vector is used for constructing an energy cost function of the CT image under the opacity, a seed point is selected at the position close to the construction to be partitioned, the optimal path, generated according to the energy cost function, between a current point and the seed point is the outline of the image of one layer of the CT image of the construction to be partitioned, secondly, the outline of a layer adjacent to the layer where the outline is located is generated, thirdly, outlines of the images of all layers in the CT image of the construction to be partitioned are generated according to the iteration method, fourthly, the outlines of the images of all the layers in the CT image of the construction to be partitioned are combined to obtain the three-dimensional construction to be partitioned. By means of the method and system for partitioning the construction in the CT image, interactive partition can be conducted on the three-dimensional CT image rapidly and accurately.