12 results about "Gamma imaging" patented technology

The invention discloses a hybrid gamma imaging method, system and device and a medium, relates to the technical field of gamma imaging, and solves the problems of low imaging performance and applicability of wide-energy-band gamma ray imaging. According to the method, a key parameter value, namely the number of sub-iterations required by a hybrid imaging method for reconstructing gamma images with different energies, can be automatically calculated, the hybrid gamma image reconstruction method is adopted, the method is suitable for an iterative image reconstruction mode, calculation is carried out according to an active coding case and a Compton case in the iteration process, and the calculation efficiency is improved. According to the method, the active coding and the Compton imaging modes are combined, and weighted summation is carried out on respective calculation results, so that the imaging performance of the gamma camera and the applicability to wide-energy-band gamma ray measurement are effectively improved, and high-performance gamma imaging with high imaging resolution and high detection sensitivity is realized.

The application discloses a method for improving the imaging resolution of a while-drilling azimuthal gamma logging device based on regularization processing, and relates to the technical field of oilfield logging, and comprises the following steps: acquiring azimuthal response sensitivity data of the while-drilling azimuthal gamma logging device; collecting multi-sector gamma imaging data of the azimuthal gamma logging at each depth according to the azimuthal response sensitivity data; and performing regularization processing on the multi-sector gamma imaging data to obtain new gamma data close to the real radioactivity intensity distribution of a formation, so that the imaging resolution of the while-drilling azimuthal gamma logging is improved. The application solves the problems of low imaging resolution and large measurement error of the existing logging.

A coded sensor gamma imager module includes a scintillation crystal layer for detecting photons and a spatial-encoding sensor element positioned above the scintillation crystal layer. The spatial-encoding sensor element includes scintillator material arranged to form a nonuniform structure in at least one dimension above the scintillation crystal layer providing coded-aperture functionality and having at least one outer edge.

This invention belongs to the field of gamma imaging technology, specifically relating to a gamma ray localization method based on a planar scintillator. The method includes the following steps: performing multi-point calibration tests on the direction and orientation of the planar scintillator using a collimated gamma ray source; calculating a normalized ratio variable; using the least squares method to fit the normalized ratio variable to a known incident position to obtain the key parameters in the two-dimensional coordinate calculation formula; training a neural network model based on a dataset; and for the gamma ray deposition location to be measured, performing rapid position calculation using the two-dimensional coordinate calculation formula, or performing high-precision position prediction using the neural network model. This invention significantly reduces the number of photoelectric readout devices and readout electronics channels while maintaining good position and energy resolution performance, thereby effectively reducing system costs. It has promising application prospects in large-area gamma imaging, radiation monitoring, and related engineering applications.

The invention belongs to the technical field of nuclear medicine imaging, and discloses a low-cost and high-dynamic-range gamma imaging method and system, and the system comprises a detector array which is formed by splicing a plurality of detector modules, the detector module comprises a silicon photomultiplier array, a pixelated scintillator array coupled to the front side of the silicon photomultiplier array and a front-end reading circuit electrically connected with the silicon photomultiplier array; the pixelated scintillator array is used for receiving and responding to the gamma ray to generate scintillation light; the silicon photomultiplier array is used for converting the scintillation light into an electric signal; the front-end reading circuit is used for preprocessing and reading out the electric signals; the upper computer is used for acquiring detection position information of a gamma event and a calibrated real energy value based on a piecewise polynomial calibration algorithm according to the read-out signal of each detector module, and performing image reconstruction in combination with an energy weight iteration reconstruction algorithm; therefore, the gamma imaging capability with low cost and high dynamic range is realized, and the imaging quality can be remarkably improved.

A multi-sector data correction method for gamma imaging while drilling includes the steps of: (a) dividing each gamma imaging sector into a plurality of counting zones; (b) counting a number of valid counting pulses for each counting zone at a predetermined time interval during MWD; (c) constructing a plurality of measurement vectors based on a value of recording times of each counting zone; (d) establishing a correction matrix with a conditional number less than a set value through an optimization algorithm; and (e) calculating a gamma intensity of each measured sector with the plurality of measurement vectors and the correction matrix as constructed, so as to complete the correction on the measurement data of each measured sector for each predetermined time interval. This method eliminate problems such as rotational measurement distortion of the gamma imaging while drilling tool and improve the accuracy of calculating the formation dip angle.

The disclosure provides a gamma imaging device and an imaging method thereof, wherein the gamma imaging device comprises a detector comprising a single crystal bar for detecting incident gamma photons of an imaging field of view relative to movement of the imaging field of view, collimation of the incident gamma photons is achieved for realizing gamma imaging, and a length-width ratio of the single crystal bar is greater than 10:1. Therefore, based on the above-mentioned gamma imaging device, a brand-new detector mode is established, an existing external mechanical collimator with low detection efficiency and being bulky and cumbersome is completely abandoned, limitations of a traditional complex detector structure and multiple electronic structures are greatly simplified, and a high-sensitivity minimalist design gamma imaging detection device can be simultaneously achieved.

This invention discloses a resistivity measurement system and method for measuring azimuth gamma. The system comprises, from top to bottom, a wireless transmitting sub, a power supply sub, an azimuth gamma measurement sub, a plug, and a resistivity measurement sub. A drilling electromagnetic resistivity meter measures resistivity and transmits the data to a resistivity acquisition sub for calculating phase and amplitude resistivity. The azimuth gamma sub acquires gamma data and calculates wellbore inclination, gravity tool face, and gamma zone. The wireless transmitting sub receives and stores data from the resistivity acquisition sub and the azimuth gamma sub, then transmits the data to the other subs above. This research also explores a specialized tool directly mounted on the drill bit for measuring the resistivity and performing gamma imaging of the formation drilled horizontally. This addresses the issue of resistivity measurement being incompatible with conventional directional drilling tools, reducing reliance on high-end imported tools and lowering system purchase and maintenance costs.

The application provides a method and system for improving the reconstruction speed and signal-to-noise ratio of a cascade gamma imaging system, and relates to the technical field of nuclear medical imaging. The method comprises the following steps: according to the acquired slit coincidence event data, combining the gamma photon interaction information and the collimator type to encode the detector module, and dividing the coincidence event data into multiple subsets according to the energy information and the encoding; directly back-projecting the coincidence events in each subset to determine the projection intersection points, and mapping the projection intersection points into corresponding voxel numbers; defining a region of interest with the voxel position represented by the voxel number as the center, and determining the boundary of the region of interest; according to the region of interest voxels, calculating the system transmission matrix corresponding to each pair of slit coincidence events in each data subset, based on the region of interest voxels, the divided data subsets and the system transmission matrix, using the ordered subset expectation maximization algorithm to perform image iterative reconstruction; thereby improving the reconstruction speed and signal-to-noise ratio of the cascade gamma imaging system.

The application discloses a kind of annular coding gamma imaging method and system.The method is:1) a circular code board is placed between a gamma detector and several radioactive sources;The circular code board is made of multiple concentric circles, and the coding mode of each concentric circle on the circular code board is set according to the principle of coding mode unrelated;2) rotate the circular code board during imaging, modulate the gamma ray flux of the gamma ray emitted by the radioactive source to reach the gamma detector;The gamma detector converts the gamma ray received during the rotation of the circular code board into count rate and sends it to the data processing unit;After the circular code board rotates a cycle, the data processing unit obtains a projection matrix D with the change of rotation angle;3) the data processing unit decodes and reconstructs to obtain the position distribution image O of the radioactive source according to the projection matrix D.The imaging flexibility of the application is greatly increased, and the cost and failure rate are also greatly reduced.

The present application belongs to the technical field of nuclear radiation detection and imaging, and particularly relates to a 3D coded gamma imaging detector based on a magic cube structure and an imaging method thereof. The gamma imaging detector adopts a spatial geometric array layout; in a plurality of spatial cells of the array, shielding units and detection modules are randomly filled heterogeneously. The shielding units adopt high-atomic-number materials, and are used for spatial modulation of omnidirectional incident gamma rays, to form anisotropic response characteristics. The detection modules are used for recording energy deposition and counting information of the gamma rays. The present application expands the traditional 2D planar coded gamma imaging into a 3D magic cube structure gamma imaging with three-dimensional spatial topology coding, and constructs a three-dimensional omnidirectional system response array by using the random distribution of the shielding units and the detection blocks in space. Without a complex coincidence electronics data acquisition system, the spatial correlation of the counts of each unit is solved, to realize accurate reconstruction of the spatial position and intensity distribution of a high-energy gamma ray source.