CN113133776B

CN113133776B - Multi-mode information calibration method and device and multi-mode imaging equipment

Info

Publication number: CN113133776B
Application number: CN202010052270.2A
Authority: CN
Inventors: 沈振华; 陈昕; 曹拓宇; 胡凌志; 刘慧�
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2020-01-17
Filing date: 2020-01-17
Publication date: 2023-05-30
Anticipated expiration: 2040-01-17
Also published as: CN113133776A

Abstract

The invention relates to a multi-mode information calibration method, a device and multi-mode imaging equipment, wherein the method comprises the following steps: acquiring a corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system; the modality of the first imaging system is different from the modality of the second imaging system; and calibrating the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation. According to the method, the computer equipment calibrates the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system, extra calibration quantity is not introduced, fluctuation of signals of the first imaging system or the second imaging system is not caused, and the energy peak position of the first imaging system or the center frequency of the second imaging system can be accurately calibrated.

Description

Multi-mode information calibration method and device and multi-mode imaging equipment

Technical Field

The present invention relates to the field of medical apparatuses, and in particular, to a method and apparatus for calibrating multi-mode information, and a multi-mode imaging device.

Background

A positron emission computed tomography (Positron Emission Computed Tomography, PET)/Magnetic Resonance (MRI) imager (Magnetic Resonance, MR) is a large-scale functional metabolism and molecular imaging diagnostic device formed by combining PET and MR, and has the examination functions of PET and MR.

During PET/MR scanning, the gradient coils are operated to generate more heat, and the accumulation of heat causes the center frequency of the MR system to drift, i.e., the MR field to drift, and at the same time, the temperature rise also causes the peak of PET to drift, so that calibration of PET and MR is required during PET/MR scanning. In the conventional technology, an MR system and a PET system are calibrated respectively, the field drift of the MR is calibrated by the change of the state of the MR system, and the energy peak of the PET is calibrated by the change of the state of the PET system. However, individual calibration of the PET system can lead to fluctuations in the MR system signals, which can lead to inaccurate scan results.

Therefore, the conventional method for calibrating PET/MR has the problem of lower calibration accuracy.

Disclosure of Invention

Based on the above, it is necessary to provide a multi-modality information calibration method, device and multi-modality imaging equipment aiming at the problem of lower calibration accuracy in the conventional PET/MR calibration method.

In a first aspect, an embodiment of the present invention provides a method for calibrating multimodal information, where the method includes:

acquiring a corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system; the modality of the first imaging system is different from the modality of the second imaging system;

and calibrating the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation.

In one embodiment, the calibrating the center frequency of the second imaging system according to the correspondence includes:

acquiring the drift amount of the energy peak position of the first imaging system;

determining a calibration amount of the center frequency of the second imaging system according to the drift amount of the energy peak position of the first imaging system and the corresponding relation;

and calibrating the center frequency of the second imaging system according to the calibration quantity of the center frequency of the second imaging system.

In one embodiment, the calibrating the energy peak position of the first imaging system according to the correspondence relationship includes:

acquiring the offset of the center frequency of the second imaging system;

Determining a calibration amount of the energy peak position of the first imaging system according to the offset of the center frequency of the second imaging system and the corresponding relation;

and calibrating the energy peak position of the first imaging system according to the calibration quantity of the energy peak position of the first imaging system.

In one embodiment, the correspondence relationship includes a mapping relationship between a drift amount of a peak position of the first imaging system and a center frequency offset amount of the second imaging system, and temperatures of the multi-mode imaging devices, respectively; the multi-mode imaging device is an integrated device composed of the first imaging system and the second imaging system.

In one embodiment, the acquiring the correspondence between the energy peak position of the first imaging system and the center frequency of the second imaging system includes:

acquiring historical drift amounts of a plurality of energy peak positions of a first imaging system in the multi-mode imaging device and temperatures of the multi-mode imaging device corresponding to the historical drift amounts;

performing linear fitting on the historical drift amount of each energy peak position and the temperature of the multi-mode imaging device corresponding to each historical drift amount to obtain a corresponding relation between the energy peak position drift amount of the first imaging system and the temperature of the multi-mode imaging device;

Acquiring historical offsets of a plurality of center frequencies of a second imaging system in the multi-modal imaging device and temperatures of the multi-modal imaging device corresponding to the historical offsets;

performing linear fitting on the historical offset of each center frequency and the temperature of the multi-mode imaging device corresponding to each historical offset to obtain a corresponding relation between the offset of the center frequency of the second imaging system and the temperature of the multi-mode imaging device;

and obtaining the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system according to the corresponding relation between the energy peak position drift amount of the first imaging system and the temperature of the multi-mode imaging device and the corresponding relation between the offset amount of the center frequency of the second imaging system and the temperature of the multi-mode imaging device.

In one embodiment, the first imaging system is a positron emission system and the second imaging system is a magnetic resonance imaging system.

In one embodiment, the energy peak position of the positron emission system is positively correlated with the number of gamma photons received by a detector of the positron emission system.

In a second aspect, an embodiment of the present invention provides a multi-modal information calibration apparatus, the apparatus including:

the acquisition module is used for acquiring the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system; the modality of the first imaging system is different from the modality of the second imaging system;

and the calibration module is used for calibrating the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation.

In a third aspect, an embodiment of the present invention provides a multi-modality imaging apparatus, including:

a positron emission system comprising a detector for receiving photons;

a magnetic resonance imaging system comprising a magnet for forming a main magnetic field;

at least one memory and at least one processor, wherein:

the at least one memory is used for storing a computer program;

the at least one processor is used for acquiring the corresponding relation between the energy peak position of photons received by the detector and the center frequency of the main magnetic field when the computer program stored in the at least one memory is called; the processor is further configured to calibrate an energy peak position of the photon by controlling the positron emission system according to the correspondence, and to calibrate a center frequency of the main magnetic field by controlling the magnetic resonance imaging system according to the correspondence.

In one embodiment, the processor is further configured to adjust a scan parameter of the magnetic resonance imaging system according to the correspondence, the scan parameter including a radio frequency emission parameter or a gradient pulse parameter

In a fourth aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, the memory storing a computer program, the processor implementing the following steps when executing the computer program:

In a fifth aspect, embodiments of the present invention provide a computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:

In the method, the device, the computer equipment and the storage medium for calibrating the multi-mode information provided by the embodiment, the computer equipment acquires the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system; the modality of the first imaging system is different from the modality of the second imaging system; and calibrating the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation. In the method, the computer equipment calibrates the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system, does not introduce extra calibration quantity or cause fluctuation of signals of the first imaging system or the second imaging system, can accurately calibrate the energy peak position of the first imaging system or the center frequency of the second imaging system, and improves the calibration accuracy of the energy peak position of the first imaging system or the center frequency of the second imaging system.

Drawings

FIG. 1 is a schematic diagram of an internal structure of a computer device according to one embodiment;

FIG. 2 is a flow chart of a method for calibrating multimodal information according to an embodiment;

FIG. 3 is a flowchart of a method for calibrating multi-modal information according to another embodiment;

FIG. 4 is a flowchart of a method for calibrating multi-modal information according to another embodiment;

FIG. 5 is a flowchart of a method for calibrating multi-modal information according to another embodiment;

FIG. 6a is a schematic diagram of an imaging device of a positron emission system according to an embodiment;

FIG. 6b is a schematic diagram of an imaging device of a magnetic resonance imaging system according to an embodiment;

FIG. 6c is a graph illustrating the relationship between the amount of energy peak position drift of the positron emission system and the temperature of the multi-modality imaging device according to one embodiment;

FIG. 6d is a schematic diagram illustrating a relationship between the center frequency offset of the MRI system and the temperature of the multi-modality imaging system according to one embodiment;

FIG. 6e is a graph showing the variation of the energy peak position of a positron emission system or the center frequency of a magnetic resonance imaging system provided by one embodiment;

fig. 7 is a schematic structural diagram of a multi-mode information calibration device according to an embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

The method for calibrating the multimodal information provided by the embodiment of the invention can be applied to computer equipment, wherein the computer equipment can be terminal equipment or a server, and the structure of the computer equipment can be as shown in fig. 1 by taking the computer equipment as the terminal equipment as an example. The computer device comprises a processor, a memory, and a computer program stored in the memory, wherein the processor is connected through a system bus, and when executing the computer program, the processor can execute the steps of the method embodiments described below. Optionally, the computer device may further comprise a network interface, a display screen and an input means. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium, which stores an operating system and a computer program, an internal memory. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface of the computer device is used for communicating with an external terminal through a network connection. Optionally, the terminal device may be, for example, a personal computer, a personal digital assistant, a tablet computer, a mobile phone, or the like, and may also be a cloud or a remote server.

In the conventional calibration of information of a multi-mode imaging device, for example, the calibration of information of a positron emission computed tomography (Positron Emission Computed Tomography, PET)/magnetic resonance (Magnetic Resonance, MR) is taken as an example, the calibration of PET and MR is mainly performed on an MR system and a PET system in the scanning process of the PET/MR device, the field drift (main magnetic field center frequency drift/offset) of the MR is calibrated by the change of the state of the MR system, and the position of the energy peak (photon energy level corresponding to the photon counting peak received by a detector) of the PET is calibrated by the change of the state of the PET system, however, the conventional calibration method of multi-mode information has the problem of lower calibration accuracy. Therefore, the embodiment of the invention provides a multi-mode information calibration method, a device, computer equipment and a storage medium, which aim to solve the technical problems in the prior art.

It should be noted that, in the method for calibrating multimodal information according to the embodiments of the present application, the execution body may be a multimodal information calibration apparatus, and the multimodal information calibration apparatus may be implemented as part or all of a computer device by software, hardware, or a combination of software and hardware. In the following method embodiments, the execution subject is a computer device.

The following describes the technical scheme of the present invention and how the technical scheme of the present invention solves the above technical problems in detail with specific embodiments. The following embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

Fig. 2 is a flow chart of a multi-mode information calibration method according to an embodiment. This embodiment relates to a specific implementation of a computer device for calibrating the energy peak position of a first imaging system or the center frequency of a second imaging system. As shown in fig. 2, the method may include:

s201, obtaining a corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system; the modality of the first imaging system is different from the modality of the second imaging system.

Specifically, the computer device obtains a correspondence between the energy peak position of the first imaging system and the center frequency of the second imaging system. Wherein the modality of the first imaging system is different from the modality of the second imaging system, for example, the first imaging system may be a Single photon emission computed tomography (Single-Photon Emission Computed Tomography, SPECT) or positron emission computed tomography (Positron Emission Computed Tomography, PET) device, and the second imaging system may be a magnetic resonance (Magnetic Resonance, MR) device, with the structural centers of the two systems aligned and constituting an integrated device. It should be noted that, the change of the energy peak position of the first imaging system and the change of the central frequency of the second imaging system of the multi-mode imaging device are affected by the state quantity of the multi-mode imaging device, for example, scanning parameters including radio frequency pulse amplitude, gradient pulse amplitude, radio frequency pulse duration, gradient pulse duration, and the like, and the temperature of the gradient, the temperature of the magnet, the temperature of the scanning bore, and the like in the multi-mode imaging system, and the corresponding relationship between the energy peak position of the first imaging system and the central frequency of the second imaging system can be obtained through the state quantity of the multi-mode imaging device.

S202, calibrating the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation.

Specifically, the computer equipment calibrates the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system; that is, according to the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system, the computer device can calibrate the energy peak position of the first imaging system and the center frequency of the second imaging system, and the calibration of the multi-mode information is realized through the mutual sharing of the system information between two different modes.

In this embodiment, the computer device calibrates the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relationship between the energy peak position of the first imaging system and the center frequency of the second imaging system, without introducing an additional calibration quantity or causing fluctuation of signals of the first imaging system or the second imaging system, so that the energy peak position of the first imaging system or the center frequency of the second imaging system can be accurately calibrated, and the calibration accuracy of the energy peak position of the first imaging system or the center frequency of the second imaging system is improved.

Fig. 3 is a flowchart of a method for calibrating multi-modal information according to another embodiment. The embodiment relates to a specific implementation process of calibrating the center frequency of a second imaging system by computer equipment according to a corresponding relation. As an optional implementation manner, as shown in fig. 3, based on the foregoing embodiment, the calibrating the center frequency of the second imaging system according to the correspondence in S202 includes:

s301, obtaining the drift amount of the energy peak position of the first imaging system.

Specifically, the computer device obtains the amount of drift in the energy peak position of the first imaging system. It can be understood that, at the initial moment of scanning by the multi-mode imaging device, the energy peak position of the first imaging system and the center frequency of the second imaging system of the multi-mode imaging device are calibrated, and in the scanning process, the drift amount of the energy peak position of the first imaging system can be obtained according to the energy peak position of the first imaging system at the initial scanning moment and the energy peak position in the scanning process.

S302, determining the calibration quantity of the center frequency of the second imaging system according to the drift quantity and the corresponding relation of the energy peak position of the first imaging system.

Specifically, the computer device determines the calibration amount of the center frequency of the second imaging system according to the drift amount of the energy peak position of the first imaging system and the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system. Optionally, the correspondence between the energy peak position of the first imaging system and the center frequency of the second imaging system includes a mapping relationship between the shift amount of the energy peak position of the first imaging system and the center frequency of the second imaging system, and the temperatures of the multi-mode imaging devices; the multi-mode imaging device is an integrated device formed by a first imaging system and a second imaging system. Optionally, the computer device may determine the temperature of the multi-mode imaging device at the current scanning time according to the drift amount of the energy peak position of the first imaging system, and determine the calibration amount of the center frequency of the second imaging system according to the temperature of the multi-mode imaging device at the current scanning time.

S303, calibrating the center frequency of the second imaging system according to the calibration quantity of the center frequency of the second imaging system.

Specifically, the computer device calibrates the center frequency of the second imaging system according to the calibration amount of the center frequency of the second imaging system. Optionally, the computer device may calibrate the center frequency of the second imaging system according to a difference between the center frequency of the second imaging system and the calibration amount of the center frequency of the second imaging system at the current scanning time, or may calibrate the center frequency of the second imaging system according to a sum of the center frequency of the second imaging system and the calibration amount of the center frequency of the second imaging system at the current scanning time.

In this embodiment, after the computer device obtains the drift amount of the energy peak position of the first imaging system, the calibration amount of the center frequency of the second imaging system can be accurately determined according to the drift amount of the energy peak position of the first imaging system and the corresponding relationship between the energy peak position of the first imaging system and the center frequency of the second imaging system, so that the center frequency of the second imaging system can be accurately calibrated according to the calibration amount of the center frequency of the second imaging system, and the accuracy of the center frequency calibration of the second imaging system is improved.

Fig. 4 is a flowchart of a method for calibrating multi-modal information according to another embodiment. The embodiment relates to a specific implementation process of calibrating the energy peak position of a first imaging system by computer equipment according to a corresponding relation. As an optional implementation manner, as shown in fig. 4, based on the foregoing embodiment, the calibrating the energy peak position of the first imaging system according to the correspondence in S202 includes:

s401, acquiring the offset of the center frequency of the second imaging system.

Specifically, the computer device obtains an offset of the center frequency of the second imaging system. It will be appreciated that, at the initial time of scanning by the multi-modality imaging apparatus, the energy peak position of the first imaging system and the center frequency of the second imaging system of the multi-modality imaging apparatus are calibrated, and during the scanning, the offset of the center frequency of the second imaging system may be obtained according to the center frequency of the second imaging system at the initial scanning time and the center frequency during the scanning.

S402, determining the calibration quantity of the energy peak position of the first imaging system according to the offset of the center frequency of the second imaging system and the corresponding relation.

Specifically, the computer device determines the calibration amount of the energy peak position of the first imaging system according to the offset of the center frequency of the second imaging system and the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system. Optionally, the correspondence between the energy peak position of the first imaging system and the center frequency of the second imaging system includes a mapping relationship between the shift amount of the energy peak position of the first imaging system and the center frequency of the second imaging system, and the temperatures of the multi-mode imaging devices; the multi-mode imaging device is a device where the first imaging system and the second imaging system are located. Optionally, the computer device may determine the temperature of the imaging device at the current scanning time according to the offset of the center frequency of the second imaging system, and determine the calibration amount of the energy peak position of the first imaging system according to the temperature of the multi-mode imaging device at the current scanning time.

S403, calibrating the energy peak position of the first imaging system according to the calibration quantity of the energy peak position of the first imaging system.

Specifically, the computer device calibrates the energy peak position of the first imaging system according to the calibration amount of the energy peak position of the first imaging system. Optionally, the computer device may calibrate the energy peak position of the first imaging system according to a difference between the energy peak position of the first imaging system and the calibration amount of the energy peak position of the first imaging system at the current scanning time, or may calibrate the energy peak position of the first imaging system according to a sum of the energy peak position of the first imaging system and the calibration amount of the energy peak position of the first imaging system at the current scanning time.

In this embodiment, after the offset of the center frequency of the second imaging system is obtained by the computer device, the calibration amount of the energy peak position of the first imaging system can be accurately determined according to the offset of the center frequency of the second imaging system and the corresponding relationship between the energy peak position of the first imaging system and the center frequency of the second imaging system, so that the energy peak position of the first imaging system can be accurately calibrated according to the calibration amount of the energy peak position of the first imaging system, and the accuracy of calibrating the energy peak position of the first imaging system is improved.

Fig. 5 is a flowchart of a method for calibrating multi-modal information according to another embodiment. The embodiment relates to a specific implementation process of acquiring a corresponding relation between an energy peak position of a first imaging system and a center frequency of a second imaging system by using computer equipment. As shown in fig. 5, based on the above embodiment, as an alternative implementation manner, S201 includes:

S501, historical drift amounts of a plurality of energy peak positions of a first imaging system in the multi-mode imaging device and temperatures of the multi-mode imaging device corresponding to the historical drift amounts are obtained.

Specifically, the computer device obtains historical drift amounts of a plurality of energy peak positions of the first imaging system in the multi-mode imaging device and temperatures of the multi-mode imaging device corresponding to the historical drift amounts. Optionally, the computer device may obtain historical drift amounts of a plurality of energy peak positions of the first imaging system in the multi-mode imaging device and temperatures of the multi-mode imaging device corresponding to the historical drift amounts in a process that the multi-mode imaging device actually works.

S502, performing linear fitting on the historical drift amount of each energy peak position and the temperature of the multi-mode imaging device corresponding to each historical drift amount to obtain a corresponding relation between the energy peak position drift amount of the first imaging system and the temperature of the multi-mode imaging device.

Specifically, the computer device performs linear fitting on the historical drift amount of each energy peak position and the temperature of the multi-mode imaging device corresponding to each historical drift amount, so as to obtain a corresponding relation between the energy peak position drift amount of the first imaging system and the temperature of the multi-mode imaging device. Optionally, the computer device may determine a parameter value corresponding to the temperature of the multi-mode imaging device corresponding to the historical drift amount of each energy peak position by performing linear fitting on the historical drift amount of each energy peak position and the temperature of the multi-mode imaging device corresponding to each historical drift amount, so as to obtain a corresponding relationship between the drift amount of the energy peak position of the first imaging system and the temperature of the multi-mode imaging device.

S503, acquiring historical offsets of a plurality of center frequencies of a second imaging system in the imaging device and temperatures of the multi-mode imaging device corresponding to the historical offsets.

Specifically, the computer device obtains the historical offsets of the plurality of center frequencies of the second imaging system in the multi-mode imaging device and the temperatures of the multi-mode imaging device corresponding to the historical offsets. Optionally, the computer device may obtain historical offsets of a plurality of center frequencies of the second imaging system in the multi-mode imaging device and temperatures of the multi-mode imaging device corresponding to the historical offsets in the actual working process of the multi-mode imaging device.

S504, performing linear fitting on the historical offset of each center frequency and the temperature of the multi-mode imaging device corresponding to the offset of each center frequency to obtain a corresponding relation between the offset of the center frequency of the second imaging system and the temperature of the multi-mode imaging device.

Specifically, the computer device performs linear fitting on the historical offset of each center frequency and the temperature of the multi-mode imaging device corresponding to each historical offset, so as to obtain a corresponding relationship between the offset of the center frequency of the second imaging system and the temperature of the multi-mode imaging device. Optionally, the computer device may determine a parameter value corresponding to the historical offset of each center frequency and the temperature of the multi-mode imaging device corresponding to each historical offset by performing linear fitting on the historical offset of each center frequency and the temperature of the multi-mode imaging device corresponding to each historical offset, so as to obtain a corresponding relationship between the offset of the center frequency of the second imaging system and the temperature of the multi-mode imaging device.

S505, obtaining the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system according to the corresponding relation between the energy peak position drift amount of the first imaging system and the temperature of the multi-mode imaging device and the corresponding relation between the offset amount of the center frequency of the second imaging system and the temperature of the multi-mode imaging device.

Specifically, the computer device obtains a corresponding relationship between the energy peak position of the first imaging system and the center frequency of the second imaging system according to a corresponding relationship between the energy peak position drift amount of the first imaging system and the temperature of the multi-mode imaging device and a corresponding relationship between the offset amount of the center frequency of the second imaging system and the temperature of the multi-mode imaging device. Optionally, the computer device may use the temperature of the multi-mode imaging device as a connection variable of the shift amount of the energy peak position of the first imaging system and the shift amount of the center frequency of the second imaging system, so as to obtain a corresponding relationship between the energy peak position of the first imaging system and the center frequency of the second imaging system.

In this embodiment, the computer device is capable of accurately obtaining the correspondence between the peak position drift amounts of the first imaging system and the temperatures of the multimode imaging devices corresponding to the plurality of peak positions of the first imaging system by fitting the obtained historical drift amounts of the plurality of peak positions of the first imaging system and the temperatures of the multimode imaging devices corresponding to the plurality of historical drift amounts, and is capable of accurately obtaining the correspondence between the shift amounts of the center frequencies of the second imaging system and the temperatures of the multimode imaging devices by fitting the obtained historical shift amounts of the plurality of center frequencies of the second imaging system and the temperatures of the multimode imaging devices corresponding to the plurality of historical shift amounts, so that the accuracy of the obtained correspondence between the peak positions of the first imaging system and the center frequencies of the second imaging system is improved according to the correspondence between the peak position drift amounts of the first imaging system and the temperatures of the multimode imaging devices, the correspondence between the shift amounts of the center frequencies of the second imaging system and the temperatures of the multimode imaging devices.

FIG. 6a is a schematic diagram of an imaging device of a positron emission system according to an embodiment; FIG. 6b is a schematic diagram of an imaging device of a magnetic resonance imaging system according to an embodiment; FIG. 6c is a graph illustrating the relationship between the amount of energy peak position drift of the positron emission system and the temperature of the multi-modality imaging device according to one embodiment; FIG. 6d is a schematic diagram illustrating a relationship between the center frequency offset of the MRI system and the temperature of the multi-modality imaging system according to one embodiment; figure 6e is a schematic diagram of the variation of the energy peak position of a positron emission system or the center frequency of a magnetic resonance imaging system provided by one embodiment. Based on the above embodiment, as an optional implementation manner, the first imaging system is a positron emission system, and the second imaging system is a magnetic resonance imaging system.

Specifically, in the multi-modality imaging apparatus, the first imaging system is a positron emission system (Positron Emission Computed Tomography, PET), and the second imaging system is a magnetic resonance imaging system (Magnetic Resonance, MR). Alternatively, the energy peak position of the PET system is positively correlated with the number of gamma photons received by the detectors of the PET system.

Referring to fig. 6a, fig. 6a is a schematic diagram of a PET imaging device according to the present embodiment, and as shown in fig. 6a, the PET imaging device 1 according to the present embodiment includes a frame 20, a signal processing unit 30, a coincidence counting unit 40, a storage unit 50, a reconstruction unit 60, a display unit 70, and an operation unit 80, with a control unit 10 as a center. Wherein a plurality Of detector rings are arranged along a central axis Of a circumference Of the gantry 20, the detector rings having a plurality Of detectors arranged on the circumference around the central axis, and the subject P is imaged in a scan Field View (FOV) surrounded by the plurality Of detectors. The specific imaging process is as follows: injecting a radioisotope-labeled pharmaceutical agent into the subject P prior to PET scanning; the detector detects paired annihilation gamma rays emitted from the inside of the subject P, and generates a pulse-like electric signal corresponding to the amount of light of the detected paired annihilation gamma rays; the pulse-like electric signal is supplied to the signal processing unit 30, and the signal processing unit 30 generates single event data (Single Event Data) from the electric signal, and in practice the signal processing unit 30 detects annihilation gamma rays by detecting that the intensity of the electric signal exceeds a threshold value; the single event data is supplied to the coincidence counting unit 40, and the coincidence counting unit 40 performs coincidence counting processing on the single event data concerning a plurality of single events. Specifically, the coincidence counting section 40 repeatedly determines event data related to 2 single events stored in a predetermined time range, for example, the time range is set to about 6ns to 18ns, from among the single event data repeatedly supplied. The paired single events are presumed to be from paired annihilation gamma rays generated from the same paired annihilation point, where the paired single events are collectively referred to as coincidence events. A Line connecting the paired detectors that detect the paired annihilation γ -rays is called a Line Of Response (LOR). In this way, the coincidence counting unit 40 counts event data (hereinafter, coincidence event data) concerning the coincidence events of the paired events constituting the LOR for each LOR, and stores the event data in the storage unit 50. The reconstruction unit 60 reconstructs image data representing the spatial distribution of the concentration of the radioisotope in the subject from coincidence event data concerning a plurality of coincidence events. In the PET image reconstruction process, the coincidence events acquired by the ideal PET are all true coincidence events, and the image reconstruction is also carried out based on the true coincidence events. As shown in fig. 6c, the abscissa represents temperature; the ordinate indicates the photons of five different energy levels respectively received by the detector method. Due to the influence of temperature, for the gamma ray photons of the same energy level, the pulse-shaped electric signals corresponding to the photons generated by the detector have errors, and the energy peak correspondence of the photons calculated by the processing circuit of the detector also has drift, namely the photon energy level calculated by the detector has deviation from the actual photon energy level, so that coincidence counting errors are caused. Wherein, the energy peak of the acquired photon can be obtained by the following way: firstly, accumulating energy spectrum of events of a detector fixed position area in a two-dimensional position image of a multi-path input position sensitive detector to obtain luminous energy spectrum peak positions corresponding to the positions of the multi-path detector. The data set of the acquired detection energy value and detection position information of the detection single event is used for generating the energy value-count value curve, wherein the abscissa of the energy value-count value curve is the energy value (the unit of the energy value is keV). One point on the energy value-count value curve is used to represent the count value of the number of times a detection annihilation event of a photon of a certain energy value occurs among all detection annihilation events detected in a lattice region corresponding to the region. And finding out the maximum counting peak value and the corresponding detection energy peak value in the energy value-counting value curve of each image area. There are many methods for finding the maximum count peak value of the energy value-count value curve of each image area and the corresponding detected energy peak value, namely, finding the highest point on the curve and the value of the abscissa corresponding to the highest point. Illustratively, a gaussian curve fitting method may be used to find the maximum count peak and its corresponding detected energy peak, where the energy peak is the energy class of gamma photons of 160KeV-195KeV received by the detector in different detections.

Referring to fig. 6b, fig. 6b is a schematic structural diagram of an MR scanning device used in the present embodiment, and as shown in fig. 6b, the MR scanning device 2 includes a signal acquisition module 130, a control module 140, a data processing module 150 and a data storage module 160. The signal acquisition module 130 includes a magnet unit 131 and a radio frequency unit 132. The magnet unit 131 mainly includes a main magnet generating a main magnetic field B0 and a gradient assembly generating a gradient field. The main magnet comprised by the magnet unit 132 may be a permanent magnet or a superconducting magnet, the gradient assembly mainly comprising gradient current Amplifiers (AMP), gradient coils, and the gradient assembly may further comprise three independent channels Gx, gy, gz, each gradient amplifier exciting a corresponding one of the gradient coil sets for generating gradient fields for generating respective spatially encoded signals for spatially localization of the magnetic resonance signals. The rf unit 132 mainly includes an rf transmitting coil for transmitting an rf pulse signal to a subject or a human body, and an rf receiving coil for receiving a magnetic resonance signal acquired from the human body, and the rf coils constituting the rf unit 132 may be divided into a volume coil and a local coil according to different functions. In one embodiment, the type of volume or local coil may be a birdcage coil, a solenoid coil, a saddle coil, a helmholtz coil, a phased array coil, a loop coil, or the like. The control module 140 may control the signal acquisition module 130, the data processing module 150, which includes the magnet unit 131 and the radio frequency unit 132, simultaneously. Illustratively, the control module 140 may receive information or pulse parameters sent by the signal acquisition module 130; in addition, the control module 140 may also control the processing of the data processing module 150. In one embodiment, the control module 140 further includes a pulse sequencer, a gradient waveform generator, a transmitter, a receiver, etc., and controls the signal acquisition module 130 to perform a corresponding scan sequence upon receiving instructions from the console from the user. The data processing module 150 may acquire a K-space dataset acquired from an imaging region of a subject and reconstruct the K-space dataset to acquire a magnetic resonance image of the imaging region. In one embodiment, the magnetic resonance principle is based on measurement The measured volume coil signals obtain the actual magnetic field strength for each location in the main magnetic field. The measured magnetic resonance signals comprise frequency information as well as phase information, optionally the actual magnetic field strength can be obtained from the frequency information, in particular as follows:

in (1) the->

The space point coordinates are in the form of polar coordinates, f is the frequency, and B is the actual magnetic field strength. Alternatively, the instantaneous actual magnetic field strength can also be obtained by phase, for example the accumulated phase variation during the time interval τ of measuring the acquisition signal is +.>

It will be appreciated, however, that if τ is sufficiently short, it is also possible to apply the formula +.>

The actual magnetic field strength is estimated. It should be noted that, since the main magnetic field drift is a gradual process with time, a set of measured magnetic resonance signals may be collected more densely, and then, in the step of processing the measured magnetic resonance signals to obtain the actual magnetic field strength, a physical model of the actual magnetic field strength may be established based on the densely collected set of measured magnetic resonance signals. Wherein the physical model simulates the variation of the actual magnetic field strength so that the distribution of the magnetic field strength over a specific time interval can be estimated and predicted, and the measured magnetic resonance signals are acquired again after the specific time interval to correct the physical model.

In this embodiment, the computer device may obtain a correspondence between the energy peak position of the PET system and the central frequency of the MR system, and calibrate the energy peak position of the PET system or the central frequency of the MR system according to the correspondence between the energy peak position of the PET system and the central frequency of the MR system (i.e. the frequency of the main magnetic field), where a specific calibration procedure may be as follows: the computer device may perform linear fitting on the temperatures of the multimode imaging devices corresponding to the historical drift amounts of the energy peak positions according to the historical drift amounts of the energy peak positions of the PET system and the temperatures of the multimode imaging devices corresponding to the historical drift amounts of the energy peak positions shown in fig. 6c, obtain a corresponding relationship between the energy peak position drift amounts of the PET system and the temperatures of the multimode imaging devices, perform linear fitting on the temperatures of the multimode imaging devices corresponding to the historical drift amounts of the energy peak positions according to the historical drift amounts of the central frequencies of the MR system and the temperatures of the multimode imaging devices shown in fig. 6d, obtain a corresponding relationship between the central frequency drift amounts of the MR system and the temperatures of the multimode imaging devices, and perform linear fitting on the temperatures of the multimode imaging devices corresponding to the historical drift amounts of the central frequencies of the MR system according to the historical drift amounts of the central frequencies, and the temperatures of the multimode imaging devices, and the peak positions of the MR system, and the energy peak position detector, and the MR system, can be calibrated at the position of the system. Illustratively, as shown in the curves a) and c) in fig. 6e, the curves a) and c) in fig. 6e are the initial energy peak position of the PET system and the energy peak position of the PET system offset at the time t, respectively, and the computer device may obtain the drift amount of the energy peak position of the PET system according to the initial energy peak position of the PET system and the energy peak position of the PET system offset at the time t; when the center frequency of the MR system is calibrated, the drift amount of the peak position of the PET system can be obtained, the calibration amount of the center frequency of the MR system is determined according to the drift amount of the peak position of the PET system and the corresponding relationship between the peak position of the PET system and the center frequency of the MR system, the center frequency of the MR system is calibrated according to the calibration amount of the center frequency of the MR system, and the b) and d) curves in fig. 6e are the initial center frequency of the MR system and the center frequency of the offset of the MR system at time t, respectively, and the computer device can obtain the offset amount of the center frequency of the MR system according to the initial center frequency of the MR system and the center frequency of the offset of the MR system at time t.

For example, the computer device may comprise a processor that may control the magnetic resonance imaging system to calibrate the center frequency of the main magnetic field according to an offset of the center frequency of the MR system: the processor can acquire the drift amount of the energy peak position of the PET system, and determine the calibration amount of the central frequency of the MR system according to the drift amount of the energy peak position of the PET system and the corresponding relation between the energy peak position of the PET system and the central frequency of the MR system; the coil current of the main magnet in the magnet unit 131 is set according to the calibration amount to homogenize the main magnetic field.

Furthermore, the processor can also adjust the scanning parameters of the magnetic resonance imaging system according to the corresponding relation between the energy peak position of the photons received by the detector and the center frequency of the main magnetic field. For example, the processor may obtain a drift amount of the energy peak position of the PET system, and determine the offset of the center frequency of the MR system based on the drift amount of the energy peak position of the PET system, the correspondence between the energy peak position of the PET system and the center frequency of the MR system. If the offset of the central frequency of the MR system is too large, the temperature of the current multi-mode imaging device is too high, and the radio frequency emission parameter or the gradient pulse parameter needs to be reduced, and meanwhile, the cooling efficiency of the gradient coil is increased; if the offset of the center frequency of the MR system is within the set threshold range, the temperature of the current multi-mode imaging device is indicated to be within an acceptable range, and the imaging scanning can be continuously performed by adopting the original scanning parameters. By the mode, the scanning efficiency can be improved on the premise of ensuring the detection accuracy of the multi-mode imaging equipment, and unnecessary scanning termination is avoided; protecting the gradient coils in the multi-modality imaging apparatus from overheating and damage.

In this embodiment, the first imaging system is a positron emission system, the second imaging system is a magnetic resonance imaging system, and the computer device can calibrate the energy peak position of the positron emission system or the center frequency of the magnetic resonance imaging system according to the corresponding relationship between the energy peak position of the positron emission system and the center frequency of the magnetic resonance imaging system, so that no extra calibration quantity is introduced, no fluctuation of signals of the positron emission system or the magnetic resonance imaging system is caused, the energy peak position of the positron emission system or the center frequency of the magnetic resonance imaging system can be accurately calibrated, and the calibration accuracy of the energy peak position of the positron emission system or the center frequency of the magnetic resonance imaging system is improved.

It should be understood that, although the steps in the flowcharts of fig. 2-5 are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in fig. 2-5 may include multiple sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, nor do the order in which the sub-steps or stages are performed necessarily occur sequentially, but may be performed alternately or alternately with at least a portion of the sub-steps or stages of other steps or steps.

Fig. 7 is a schematic structural diagram of a multi-mode information calibration device according to an embodiment. As shown in fig. 7, the apparatus may include: an acquisition module 10 and a calibration module 11.

Specifically, the acquiring module 10 is configured to acquire a correspondence between an energy peak position of the first imaging system and a center frequency of the second imaging system; the modality of the first imaging system is different from the modality of the second imaging system;

and the calibration module 11 is used for calibrating the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation.

The multi-mode information calibration device provided in this embodiment may execute the above method embodiment, and its implementation principle and technical effects are similar, and will not be described herein.

On the basis of the above embodiment, optionally, the above calibration module 11 includes: the device comprises a first acquisition unit, a first determination unit and a first calibration unit.

Specifically, a first obtaining unit is configured to obtain a drift amount of an energy peak position of a first imaging system;

the first determining unit is used for determining the calibration quantity of the center frequency of the second imaging system according to the drift quantity and the corresponding relation of the energy peak position of the first imaging system;

and the first calibration unit is used for calibrating the center frequency of the second imaging system according to the calibration quantity of the center frequency of the second imaging system.

On the basis of the above embodiment, optionally, the above calibration module 11 includes: the second acquisition unit, the second determination unit and the second calibration unit.

Specifically, the second acquisition unit is used for acquiring the offset of the center frequency of the second imaging system;

the second determining unit is used for determining the calibration quantity of the energy peak position of the first imaging system according to the offset of the center frequency of the second imaging system and the corresponding relation;

and the second calibration unit is used for calibrating the energy peak position of the first imaging system according to the calibration quantity of the energy peak position of the first imaging system.

On the basis of the above embodiment, optionally, the correspondence includes a mapping relationship between a drift amount of a peak position of the first imaging system and a center frequency of the second imaging system, and temperatures of the multi-mode imaging devices, respectively; the multi-modality imaging device is an integrated device composed of a first imaging system and a second imaging system.

On the basis of the above embodiment, optionally, the above acquisition module 10 includes: the device comprises a third acquisition unit, a first fitting unit, a fourth acquisition unit, a second fitting unit and a fifth acquisition unit.

Specifically, the third obtaining unit is configured to obtain historical drift amounts of a plurality of energy peak positions of the first imaging system in the multi-mode imaging device, and temperatures of the multi-mode imaging device corresponding to the historical drift amounts;

the first fitting unit is used for linearly fitting the historical drift amount of each energy peak position and the temperature of the multi-mode imaging device corresponding to each historical drift amount to obtain the corresponding relation between the energy peak position drift amount of the first imaging system and the temperature of the multi-mode imaging device;

a fourth obtaining unit, configured to obtain historical offsets of a plurality of center frequencies of a second imaging system in the multi-mode imaging device, and temperatures of the multi-mode imaging device corresponding to the historical offsets;

the second fitting unit is used for linearly fitting the historical offset of each center frequency and the temperature of the multi-mode imaging device corresponding to each historical offset to obtain the corresponding relation between the offset of the center frequency of the second imaging system and the temperature of the multi-mode imaging device;

And a fifth obtaining unit, configured to obtain a corresponding relationship between the energy peak position of the first imaging system and the center frequency of the second imaging system according to a corresponding relationship between the energy peak position drift amount of the first imaging system and the temperature of the multi-mode imaging device, and a corresponding relationship between the offset amount of the center frequency of the second imaging system and the temperature of the multi-mode imaging device.

Alternatively, the first imaging system may be a positron emission system and the second imaging system a magnetic resonance imaging system.

Alternatively, the energy peak position of the positron emission system is positively correlated with the number of gamma photons received by the detector of the positron emission system.

For specific limitations of the multi-modal information calibration apparatus, reference may be made to the above limitations of the multi-modal information calibration method, and no further description is given here. The modules in the multi-modal information calibration apparatus may be implemented in whole or in part by software, hardware, or a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In one embodiment, there is provided a multi-modality imaging apparatus including:

a positron emission system comprising a detector for receiving photons;

a magnetic resonance imaging system comprising a main magnet for forming a main magnetic field;

at least one memory and at least one processor, wherein:

at least one memory for storing a computer program;

the at least one processor is used for acquiring the corresponding relation between the energy peak position of photons received by the detector and the center frequency of the main magnetic field when the computer program stored in the at least one memory is called; the processor is also used for calibrating the energy peak position of photons controlled by the positron emission system according to the corresponding relation and calibrating the center frequency of the main magnetic field controlled by the magnetic resonance imaging system according to the corresponding relation.

The multi-mode imaging device provided in this embodiment may perform the above-described method embodiments, and its implementation principle and technical effects are similar, and will not be described herein.

Based on the above embodiment, as an optional implementation manner, the processor is further configured to adjust a scan parameter of the magnetic resonance imaging system according to the correspondence relationship, where the scan parameter includes a radio frequency emission parameter or a gradient pulse parameter.

In one embodiment, a computer device is provided comprising a memory and a processor, the memory having stored therein a computer program, the processor when executing the computer program performing the steps of:

The computer device provided in the foregoing embodiments has similar implementation principles and technical effects to those of the foregoing method embodiments, and will not be described herein in detail.

In one embodiment, a computer readable storage medium is provided having a computer program stored thereon, which when executed by a processor, performs the steps of:

The computer readable storage medium provided in the above embodiment has similar principle and technical effects to those of the above method embodiment, and will not be described herein.

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the various embodiments provided herein may include non-volatile and/or volatile memory. The nonvolatile memory can include Read Only Memory (ROM), programmable ROM (PROM), electrically Programmable ROM (EPROM), electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data Rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), memory bus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), among others.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A method for calibrating multimodal information, the method comprising:

acquiring a corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system; the modality of the first imaging system is different from the modality of the second imaging system; the corresponding relation comprises a mapping relation between the drift amount of the peak position of the first imaging system and the offset of the center frequency of the second imaging system and the temperature of the multi-mode imaging device; the multi-mode imaging device is an integrated device formed by the first imaging system and the second imaging system;

According to the corresponding relation, calibrating the energy peak position of the first imaging system or the center frequency of the second imaging system;

the obtaining the correspondence between the energy peak position of the first imaging system and the center frequency of the second imaging system includes:

2. The method of claim 1, wherein calibrating the center frequency of the second imaging system according to the correspondence comprises:

3. The method of claim 1, wherein calibrating the energy peak position of the first imaging system according to the correspondence comprises:

acquiring the offset of the center frequency of the second imaging system;

4. The method of claim 2, wherein the obtaining the amount of drift in the energy peak position of the first imaging system comprises:

and acquiring the drift amount of the energy peak position of the first imaging system according to the energy peak position of the first imaging system at the initial scanning moment and the energy peak position in the scanning process.

5. The method of claim 3, wherein the obtaining an offset of a center frequency of the second imaging system comprises:

and acquiring the offset of the center frequency of the second imaging system according to the center frequency of the second imaging system at the initial scanning moment and the center frequency in the scanning process.

6. The method of claim 1, wherein the first imaging system is a positron emission system and the second imaging system is a magnetic resonance imaging system.

7. The method of claim 6, wherein the energy peak position of the positron emission system is positively correlated with the number of gamma photons received by a detector of the positron emission system.

8. A multi-modal information calibration apparatus, the apparatus comprising:

the acquisition module is used for acquiring the corresponding relation between the energy peak position of the first imaging system and the center frequency of the second imaging system; the modality of the first imaging system is different from the modality of the second imaging system; the corresponding relation comprises a mapping relation between the drift amount of the peak position of the first imaging system and the offset of the center frequency of the second imaging system and the temperature of the multi-mode imaging device; the multi-mode imaging device is an integrated device formed by the first imaging system and the second imaging system;

the calibration module is used for calibrating the energy peak position of the first imaging system or the center frequency of the second imaging system according to the corresponding relation;

9. A multi-modality imaging apparatus, characterized in that the multi-modality imaging apparatus comprises:

a positron emission system comprising a detector for receiving photons;

at least one memory and at least one processor, wherein:

The at least one memory is used for storing a computer program;

the at least one processor is used for acquiring the corresponding relation between the energy peak position of photons received by the detector and the center frequency of the main magnetic field when the computer program stored in the at least one memory is called; the processor is further configured to calibrate an energy peak position of the photon by controlling the positron emission system according to the correspondence, and to calibrate a center frequency of the main magnetic field by controlling the magnetic resonance imaging system according to the correspondence; the corresponding relation comprises a mapping relation between the drift amount of the energy peak position of photons received by the detector and the offset of the center frequency of the main magnetic field and the temperature of the multi-mode imaging device; the multi-mode imaging device is integrated equipment consisting of the positron emission system and the magnetic resonance imaging system;

the corresponding relation between the energy peak position of the photon received by the acquisition detector and the center frequency of the main magnetic field comprises the following steps:

acquiring historical drift amounts of a plurality of energy peak positions of photons received by the detector and temperatures of the multi-mode imaging equipment corresponding to the historical drift amounts;

Performing linear fitting on the historical drift amount of each energy peak position and the temperature of the multi-mode imaging device corresponding to each historical drift amount to obtain a corresponding relation between the energy peak position drift amount of photons received by the detector and the temperature of the multi-mode imaging device;

acquiring historical offsets of a plurality of center frequencies of the main magnetic field and temperatures of the multi-mode imaging equipment corresponding to the historical offsets;

performing linear fitting on the historical offset of each center frequency and the temperature of the multi-mode imaging device corresponding to each historical offset to obtain a corresponding relation between the offset of the center frequency of the main magnetic field and the temperature of the multi-mode imaging device;

and obtaining the corresponding relation between the energy peak position of the photon received by the detector and the central frequency of the main magnetic field according to the corresponding relation between the energy peak position drift amount of the photon received by the detector and the temperature of the multi-mode imaging device and the corresponding relation between the offset amount of the central frequency of the main magnetic field and the temperature of the multi-mode imaging device.

10. The multi-modality imaging apparatus of claim 9, wherein the processor is further configured to adjust scan parameters of the magnetic resonance imaging system according to the correspondence, the scan parameters including radio frequency emission parameters or gradient pulse parameters.