CN119355608A - Magnetic resonance gating method, device, terminal and medium based on laser speckle image - Google Patents
Magnetic resonance gating method, device, terminal and medium based on laser speckle image Download PDFInfo
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Abstract
本发明提供的基于激光散斑图像的磁共振门控方法、装置、终端及介质，具体涉及图像处理和生理监测技术领域，方案包括：基于预设的时空映射模型，利用单个相机采集预设时间段内在激光灯照射下心脏的离焦干涉散斑图像序列；基于离焦干涉散斑图像序列，获得心脏的复合运动信号；基于复合运动信号，确定心脏的时序相位特征；响应于检测到时序相位特征，利用预设的门控策略提取心脏振动信号和呼吸运动信号。该方案所提出的新型的复合式门控策略仅依赖单个离焦相机，具有非接触、高精度、对由磁场引起的扰动具有鲁棒性的优点，可简化磁共振流程，提供更舒适的使用体验，能够有效消除磁共振成像过程中存在的呼吸、心脏运动伪影。
The magnetic resonance gating method, device, terminal and medium based on laser speckle image provided by the present invention specifically relate to the field of image processing and physiological monitoring technology, and the scheme includes: based on a preset spatiotemporal mapping model, using a single camera to collect a sequence of defocused interference speckle images of the heart under the irradiation of a laser light within a preset time period; based on the sequence of defocused interference speckle images, obtaining a composite motion signal of the heart; based on the composite motion signal, determining the timing phase characteristics of the heart; in response to the detection of the timing phase characteristics, using a preset gating strategy to extract the heart vibration signal and the respiratory motion signal. The new composite gating strategy proposed in this scheme relies only on a single defocus camera, has the advantages of non-contact, high precision, and robustness to disturbances caused by the magnetic field, can simplify the magnetic resonance process, provide a more comfortable use experience, and can effectively eliminate the respiratory and cardiac motion artifacts present in the magnetic resonance imaging process.
Description
Technical Field
The invention relates to the technical field of image processing and physiological monitoring, in particular to a magnetic resonance gating method, a device, a terminal and a medium based on laser speckle images.
Background
Cardiovascular magnetic resonance imaging (Cardiovascular Magnetic Resonance, CMR) is a non-invasive medical imaging technique that can provide high resolution cardiovascular images for assessing cardiac structure and function, and related vascular systems such as the aorta, coronary arteries, etc., providing important support for diagnosis and treatment of cardiovascular disease, but CMR imaging often suffers from motion artifacts.
In the prior art, motion artifacts are often overcome by a gating technology, and the gating technology is to trigger image acquisition and heart cycle synchronization by using an external signal, so that the heart cycle motion artifacts are effectively reduced. Common gating techniques are Electrocardiograph (ECG) gating and pulse wave (Photoplethysmography, PPG) gating, where ECG gating is susceptible to interference from strong magnetic fields, PPG gating has conduction time differences, and both are prone to cardiac motion artifacts. Therefore, the quality of the cardiac magnetic resonance image acquired by the existing electrocardiograph gating technology is poor, and the cardiac motion signal cannot be accurately extracted.
Disclosure of Invention
In view of the shortcomings of the prior art, the invention aims to provide a magnetic resonance gating method, a device, a terminal and a medium based on laser speckle images, which aim to solve the problems that acquired heart magnetic resonance images in the prior art are poor in quality and heart motion signals cannot be accurately extracted.
To achieve the above object, a first aspect of the present invention provides a magnetic resonance gating method based on laser speckle images, applied to a magnetic resonance gating apparatus based on laser speckle images, the apparatus comprising a camera and a laser lamp, comprising the steps of:
Based on a preset space-time mapping model, acquiring a defocused interference speckle image sequence of the heart under the irradiation of the laser lamp in a preset time period by using the camera;
based on the defocusing interference speckle image sequence, obtaining a composite motion signal of the heart, wherein the composite motion signal is formed based on heart motion and respiratory motion together;
Determining a temporal phase characteristic of the heart based on the composite motion signal;
And in response to detecting the time sequence phase characteristic, extracting a heart vibration signal and a respiratory motion signal by using a preset gating strategy.
Optionally, the acquiring, by using the camera, a sequence of defocused interference speckle images of the heart under irradiation of the laser lamp within a preset time period based on a preset space-time mapping model includes:
Irradiating a preset position of the heart by using the laser lamp based on a preset space-time mapping model;
and acquiring a defocusing interference speckle image sequence of the heart within a preset time period by using the camera.
Optionally, the obtaining the composite motion signal of the heart based on the defocused interference speckle image sequence includes:
Obtaining a defocused speckle signal based on the defocused interference speckle image sequence;
and extracting the out-of-focus speckle signals by using an optical flow algorithm to obtain a composite motion signal of the heart.
Optionally, the determining a time-series phase characteristic of the heart based on the composite motion signal includes:
Dividing the composite motion signal according to the motion phases of the heart, and determining composite motion signal fragments corresponding to each motion phase of the heart;
And extracting features according to the time sequence of the composite motion signal segments corresponding to all the motion phases, and determining the time sequence phase features of the heart.
Optionally, the extracting the cardiac vibration signal and the respiratory motion signal with a preset gating strategy in response to detecting the timing phase feature includes:
responding to detection of preset respiratory motion feature points and preset heartbeat motion feature points;
When the respiratory motion feature points are detected, triggering nuclear magnetic resonance scanning to obtain heartbeat image data by corresponding phase images of each heartbeat motion feature point if one or more heartbeat motion feature points are detected in the same respiratory period;
Reconstructing the heartbeat image data based on the time sequence phase characteristics to obtain a heart motion signal;
a respiratory motion signal is obtained based on the composite motion signal and the cardiac motion signal.
Optionally, the extracting the cardiac vibration signal and the respiratory motion signal with a preset gating strategy in response to detecting the timing phase feature includes:
responding to detection of preset respiratory motion feature points and preset heartbeat motion feature points;
when the respiratory motion feature points are detected, triggering nuclear magnetic resonance to scan images of the whole heartbeat motion period if the heartbeat motion feature points are detected in the same respiratory period, and obtaining heartbeat image data;
Reconstructing the heartbeat image data based on the time sequence phase characteristics to obtain a heart motion signal;
a respiratory motion signal is obtained based on the composite motion signal and the cardiac motion signal.
A second aspect of the invention provides a magnetic resonance gating apparatus based on laser speckle images, the apparatus comprising at least one camera and at least one laser lamp, further comprising:
The space-time mapping model construction module is used for constructing a space-time mapping model based on the positions of the camera and the heart of the subject;
the defocusing speckle image acquisition module is used for acquiring a defocusing interference speckle image sequence of the heart irradiated by the laser lamp within a preset time period by using the camera based on a preset space-time mapping model;
The compound motion signal extraction module is used for obtaining a compound motion signal of the heart based on the defocusing interference speckle image sequence, and the compound motion signal is formed based on heart motion and respiratory motion together;
a time sequence phase feature extraction module for determining a time sequence phase feature of the heart based on the composite motion signal;
And the signal separation module is used for responding to the detection of the time sequence phase characteristic and extracting a heart vibration signal and a respiratory motion signal by utilizing a preset gating strategy.
A third aspect of the present invention provides a terminal comprising a memory, a processor and a laser speckle image based magnetic resonance gating program stored on the memory and executable on the processor, the laser speckle image based magnetic resonance gating program implementing the steps of any one of the above laser speckle image based magnetic resonance gating methods when executed by the processor.
A fourth aspect of the present invention provides a computer readable storage medium having stored thereon a magnetic resonance gating program based on a laser speckle image, which when executed by a processor, implements the steps of any one of the above-described magnetic resonance gating methods based on a laser speckle image.
Compared with the prior art, the beneficial effects of this scheme are as follows:
The invention mainly uses the Camera which is adjusted to the defocusing state to shoot the laser interference speckle image reflected by the chest of the human body, the cardiovascular magnetic resonance gating of the laser speckle heart vibration image does not need to contact the human body and is not interfered by a strong magnetic field of magnetic resonance, the Camera-based heart vibration image (Camera-Seismocardiography, camera-SCG) can be accurately reconstructed by analyzing continuous speckle images, and the magnetic resonance system is triggered based on the reconstructed Camera-based heart vibration image signal according to the constructed novel composite gating strategy, so that the heart motion signal and the respiratory motion signal are synchronously extracted according to the laser speckle motion, and the motion artifact caused by heart pulsation can be effectively lightened. The novel composite gating strategy provided by the invention only depends on a single defocusing camera, has the advantages of non-contact, high precision and robustness to disturbance caused by a magnetic field, can simplify a magnetic resonance flow, provides more comfortable use experience, and can effectively eliminate respiratory and cardiac motion artifacts in the magnetic resonance imaging process.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a cardiovascular magnetic resonance image;
FIG. 2 is a flow chart of a magnetic resonance gating method based on laser speckle images of the present invention;
FIG. 3 is a schematic diagram of rotational motion along the X-axis/Y-axis of a spatio-temporal mapping model between heart beat and speckle pixel motion of the present invention;
FIG. 4 is a schematic diagram of translational motion along the Z-axis of a spatio-temporal mapping model between cardiac beat and speckle pixel motion of the present invention;
FIG. 5 is a schematic representation of out-of-focus speckle imaging and corresponding optical flow fields of the present invention;
FIG. 6 is a schematic illustration of the various motion phases of the heart of the present invention;
FIG. 7 is a waveform diagram of a normalized composite cardiac motion signal of the present invention;
FIG. 8 is a schematic diagram of a comparison of multiple cardiovascular magnetic resonance gating triggering mechanisms based on cardiac motion signals according to the present invention;
FIG. 9 is a schematic diagram of a magnetic resonance gating apparatus based on laser speckle images according to the present invention;
fig. 10 is a schematic diagram of a terminal structure according to the present invention.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular device structures, techniques, etc. in order to provide a thorough understanding of embodiments of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be further understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.
As used in this specification and the appended claims, the term "if" may be interpreted as "when..once" or "in response to a determination" or "in response to detection" depending on the context. Similarly, the phrase "if a condition or event described is determined" or "if a condition or event described is detected" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon detection of a condition or event described" or "in response to detection of a condition or event described".
The following description of the embodiments of the present invention will be made more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown, it being evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present invention is not limited to the specific embodiments disclosed below.
The problems that the quality of a heart magnetic resonance image acquired by the existing electrocardio gating technology is poor, and a heart motion signal cannot be accurately extracted are solved, and the reasons that the heart magnetic resonance image quality is poor are mainly that the heart fluctuation, the respiratory motion and other limb motions cause tissue position and shape changes, image phase encoding errors or geometric deformation are caused, and motion artifacts such as blurring, ghosting, stripes or flickering are caused to the image, as shown in fig. 1. Therefore, the invention provides a magnetic resonance gating method based on laser speckle images, which mainly uses an defocusing Camera to shoot laser interference speckle images reflected by the chest of a human body, and the cardiac vascular magnetic resonance gating of the defocusing Camera laser speckle heart vibration image does not need to contact the human body, is not interfered by a magnetic resonance strong magnetic field, can accurately reconstruct heart motion by analyzing continuous speckle images, and can effectively reduce motion artifacts caused by heart pulsation by triggering a magnetic resonance system to acquire images based on reconstructed Camera-SCG signals. The combined gating strategy provided by the invention only depends on a single defocusing camera, has the advantages of non-contact, high precision and robustness to disturbance caused by a magnetic field, can synchronously extract heart motion and respiratory motion from the motion of laser speckles, realizes novel combined gating, can simplify the magnetic resonance process, provides more comfortable use experience, and can effectively eliminate respiratory and cardiac motion artifacts in the magnetic resonance imaging process.
The embodiment of the invention provides a magnetic resonance gating method based on laser speckle images, which is deployed on electronic equipment such as a computer and a server and is applied to a scene for monitoring heart movement and respiratory movement of a person or animal and the like, and aims at the situation that the heart of the person is irradiated by single-band laser to acquire defocused interference speckle images for analyzing heart composite operation signals (including heart movement signals and respiratory movement signals) of the person.
The method is applied to a magnetic resonance gating device based on laser speckle images, the device comprises a camera and a laser lamp, the laser lamp is used for emitting laser with a certain wave band to the position of the heart of a subject, and the camera is used for collecting defocused speckle images of the heart of the subject under the irradiation of the laser lamp. The device also comprises a space-time mapping model construction module, a defocusing speckle image acquisition module, a composite motion signal extraction module, a time sequence phase characteristic extraction module and a signal separation module, wherein the functions of the modules are described in detail in the following implementation process of the magnetic resonance gating method based on the laser speckle image.
Based on the device, the detailed flow of the magnetic resonance gating method based on the laser speckle image in the embodiment is shown in fig. 2, and specifically is as follows:
And step 100, acquiring a defocusing interference speckle image sequence of the heart under the irradiation of the laser lamp in a preset time period by using the camera based on a preset space-time mapping model.
Specifically, since the condition that diffuse reflection occurs is that the wavelength of light is smaller than the undulating height of the heart surface of the subject, heart pulsation will be shown on the chest surface in the form of microscopic vibration with an amplitude of 0.2-0.5mm, so that in principle, light in the visible light band can be used in the scheme, and in order to better extract the speckle pattern generated under irradiation of light later, the embodiment adopts laser as the light source, and since the laser only contains light with a single wavelength, the single property is good, and the accurate separation of the speckle pattern corresponding to the laser wavelength is facilitated. Through a great deal of researches and experimental analysis, when the camera is in an out-of-focus state, interference speckles formed in video after laser irradiation is reflected on the surface of a human body are not blurred, but are granular with alternate brightness and strong contrast. Weak chest motion caused by heart beating changes the reflection direction of the laser light at its surface, resulting in a spatially distributed variation of speckle interference fringes in the reflected light field, and the intensity of the speckle interference fringe variation increases significantly with increasing defocus of the camera, where defocus represents the ratio of the distance between the heart of the subject and the focal plane to the distance between the camera and the focal plane.
Therefore, the present embodiment constructs a spatiotemporal mapping model as shown in fig. 3 in advance, specifically, the camera and the heart of the subject are disposed on both sides of the focal plane of the camera. When the camera is out of focus, the subject's heart moves to a distance from the focal planeIs a distance of (3). Taking the example of the heart of a subject rotating along the Y-axis, the initial incident angle of the laser isThe imaging angle of the camera isWhen the heart of the subject rotates a small angle along the Y-axisIn this case, the incident angle of the laser beam is also changed by the same angle. The laser light is actually only irradiated on a single pixel point of the heart of the subject, but since the pixel point is not on the focal plane, a speckle is generated on the camera imaging plane, and the radial displacement of the speckle relative to the single pixel point isThe radial displacement is affected by two factors, one is that the rotational motion of the subject's heart itself causes the same angular change in the subject's heart surface relative to the orientation of the light source and sensorIt is apparent that the number of the components,Secondly, the change of the irradiation angle caused by the rotation motion can cause the reflected light to generate additional rotation. In order to be able to observe the same speckle after the rotation of the heart of the subject, the constraint that the speckle before and after the rotation have the same initial phase difference (i.e., the optical path difference before and after the rotation is unchanged) should be satisfied, so that the change in the irradiation angle is defined according to the constraint to satisfy the form as shown in the formula (1):
(1),
typically the subject's heart is rotated through a small angle, obtainable by the equivalent infinitesimal replacement principle Radial displacement of laser speckle on camera imaging planeThe expression of (2) is shown as formula (2), namely:
(2),
wherein, Representing the distance between the heart and the focal plane of the subject,Representing the distance between the camera lens and the focal plane,Representing the focal length.
Taking into account the constraint that the light irradiation angle is equal to the imaging angle of the camera, equation (2) can be simplified as:
(3)。
Likewise, when the heart of the subject rotates along the X-axis, the motion of the pixels in the Y-direction of the camera imaging plane is caused, and the expression of the motion displacement is as in expression (2).
As shown in fig. 4, when the camera is imaging vertically) Translational movement of a subject's heartThe motion of pixels on the imaging plane of the camera is not caused, and when an included angle exists in the imaging of the camera, the camera is prevented from moving) The light rays irradiated to the same position on the heart surface of the subject can have an angle ofAnd the magnitude of which is proportional to the magnitude of the out-of-plane displacement dz of the heart of the subject). Wherein, Is the illumination distance. As can be seen from the above analysis,And (3) withThe values of the two are equal to each other,The expression of (2) is the same as that of formula (1). Thus, the displacement of the speckle in the camera sensor along the X-axis can be obtainedAs shown in formula (4):
(4)。
since the sensitivity to out-of-plane rotation is much greater than other motions when the camera is highly out-of-focus, then Far smaller thanThe displacement of the pixels in the X-direction on the camera plane can be reduced to:
(5),
wherein, Is a constant.
Based on the above analysis, the sensitivity of the pixels on the camera imaging plane to heart motion of the subject in both the X-axis direction and the Y-axis direction is positively correlated with the defocus level of the camera, where defocus level represents the distance between the subject's heart and the focal planeAnd the distance between the camera and the focal planeRatio of (2), i.e. Therefore, the embodiment realizes the sensitivity setting of different degrees of heart motion of a subject by adjusting the defocus degree of the camera through the space-time mapping model construction module, so that the focal plane is positioned between the camera and the heart of the subject, the defocus degree is set in a corresponding ratio range according to the sensitivity requirement of the heart motion of the subject, the spatial position relationship between the camera and the heart is determined, the vibration signals of the heart in a preset time period are acquired based on the spatial position relationship, the defocus speckle images in the preset time period are acquired by the camera, the time sequence relationship between the vibration signals of the heart and the corresponding defocus speckle image motions in the preset time period is determined, and the space-time mapping model between the heart and the speckle pixel motions is constructed based on the spatial position relationship and the time sequence relationship. The motion monitoring mode of the heart of the subject in this embodiment is quite different from the motion monitoring in the conventional video imaging, in which the sensitivity of the motion monitoring is lower as the camera is farther from the heart of the subject. Therefore, the imaging mode of defocusing interference speckle is particularly suitable for monitoring weak physiological motion at a long distance.
Then, an initial experiment is performed on the imaging effect of the constructed space-time mapping model, and the defocusing degree of the camera is adjusted by controlling the distance between the focal plane of the camera and the lens in the experiment. As shown in fig. 5, in the two experiments, the laser lamp emits laser light in the same wave band, but the distance between the heart and the focal plane is different, which are respectively called an object distance experiment and an object distance near experiment, by comparing the light interference results of the two experiments, it is known that the two experiments have the condition of same-direction interference and reverse interference, compared with the object distance near experiment, the particle size of speckle generated by the object distance experiment is larger, and the movement of the optical flow field is more obvious. It can be seen that in monitoring the laser interferometry, as the distance between the heart and the focal plane increases (i.e. the object distance increases), the particle size of the obtained speckle is also increasing and the speckle motion is more sensitive (i.e. the arrow representing the motion in the optical flow field is longer), consistent with the deduction conclusion related to the above-mentioned spatio-temporal mapping model between heart beat and speckle pixel motion. Based on this, the present embodiment lays the camera at a suitable distance from the subject according to the calculation accuracy and sensitivity requirements to meet the multiple requirement of interference speckle amplification for heart vibration.
And acquiring a defocusing interference speckle image sequence reflected by the chest of a human body in a preset time period through a defocusing speckle image acquisition module by using a defocusing camera, wherein the defocusing interference speckle image sequence comprises defocusing interference speckle of a reflection signal formed under the irradiation of laser light of a single wave band emitted by the laser lamp, and the preset time period refers to a period of time corresponding to a plurality of heart pulse periods so as to ensure that a complete heart motion signal and a respiratory motion signal can be extracted from the defocusing interference speckle image sequence. The embodiment adopts a single defocusing camera to collect defocusing interference speckle images of the heart part, has the advantages of non-contact, high precision and robustness to disturbance caused by a magnetic field, and has smaller physiological time delay and can capture more accurate and sensitive heart motion state compared with pulse waves used in pulse wave gating technology due to weak thoracic vibration caused by heart beating caused by laser reflection.
And step 200, obtaining a composite motion signal of the heart based on the defocusing interference speckle image sequence, wherein the composite motion signal is formed based on the heart motion and the respiratory motion.
Specifically, because defocusing interference speckle corresponding to the laser wave band can be generated under the irradiation of laser emitted by the laser lamp, each pixel in the defocusing speckle image is composed of pixel values of three channels of RGB, the defocusing speckle signals contained in each defocusing speckle image in the defocusing interference speckle image sequence are extracted according to the pixel channels through the composite motion signal extraction module, and are extracted from the laser speckle image in an optical mode and are not interfered by a magnetic resonance system self magnetic field, the defocusing speckle signals have high precision, the defocusing speckle signals are subjected to signal extraction by utilizing an optical flow algorithm to obtain a composite motion signal, the composite motion signal is formed by the combination of heart motion and respiratory motion, namely the composite motion signal comprises a heart vibration signal and a respiratory motion signal, specifically, the motion amplitude of the defocusing speckle signals in the X direction and the Y direction is calculated by adopting an optical flow method and is cascaded into a motion amplitude sequence, and the motion amplitude sequence in the X direction and the Y direction is divided into a sliding windowEach segment, expressed asFor all of each segmentAndDetermining the angle of motion of the out-of-focus speckle signal using equation (6)WhereinRepresenting a ninety-digit magnitude value in a corresponding quadrant,The number of bits to be taken in is indicated,Representing four quadrants in a cartesian rectangular coordinate system,The number of the quadrant is indicated,。
(6),
Wherein, Representing the quadrant with the maximum ninety digits of the four quadrants of the cartesian coordinate system,Representing the coordinates of any two-dimensional spatial point in a cartesian rectangular coordinate system,AndRespectively representing the motion amplitude of the defocused speckle image in the X direction and the Y direction relative to the defocused speckle image of the previous frame,Representing the number of segments divided using sliding windows, the argmax function returnsTaking the corresponding parameter when the maximum value is taken.
Obtaining the movement angle of the defocused speckle signalThen, using formula (7)AndComposite motion signal synthesized into heartI.e., camera-SCG signal.
(7),
Wherein, AndComposite motion signals representing all sliding windows separatelyThe magnitude of the motion in the X direction and the magnitude of the motion in the Y direction.
It can be seen that the nature of the Camera-SCG signal is the regular pixel motion information in the speckle image.
And step S300, determining the time sequence phase characteristic of the heart based on the composite motion signal.
Specifically, since the motion phases of the heart mainly include systole and diastole, these two phases may be further subdivided into motion phases such as atrial systole (corresponding to P-wave on electrocardiogram), ventricular isovolumetric systole (QRS complex starts to S1 heart sound), ventricular fast ejection phase, ventricular slow ejection phase, ventricular isovolumetric diastole (S2 heart sound starts to T-wave), ventricular fast filling phase and ventricular slow filling phase (atrial systole), wherein the start or end of each motion phase in one heart beat motion cycle includes mitral valve closing (MITRAL VALVE Closure, MC) point, isovolumetric contraction (Inferior Vena Cava, IVC) point, aortic valve Opening (Aortic Valve Opening, AO) point, fast ejection (Rapid Ejection, RE) point, aortic valve closing (Aortic Valve Closure, AC) point, mitral valve Opening (MITRAL VALVE Opening, MO) point, fast filling (RAPID FILLING, RF) point, and the like, as shown in fig. 6.
Therefore, the embodiment divides the composite motion signal according to the motion phases of the heart through the time sequence phase feature extraction module to determine the composite motion signal segments corresponding to each motion phase of the heart, and extracts the features according to the time sequence of the composite motion signal segments corresponding to all the motion phases to determine the time sequence phase features of the heart, including the time sequence feature data of different time phases such as time marks, waveform features and frequency features. Wherein, the time mark is used for representing the starting time and the ending time of each stage, and can be determined by the R wave crest, the P wave starting point, the S1 heart sound, the S2 heart sound and the like on the Camera-SCG. Waveform characteristics are used to represent waveform morphology, amplitude, width, etc. at each stage, such as morphology of QRS complex on Camera-SCG, intensity and duration of S1 heart sound and S2 heart sound. The frequency characteristic is used to represent the vibration caused by the heart motion or the frequency change of the blood flow velocity, and can be obtained by a spectrum analysis method and the like.
And step 400, responding to the detection of the time sequence phase characteristic, and extracting a heart vibration signal and a respiratory motion signal by using a preset gating strategy.
In particular, since the motion of the thoracic plane is a complex motion consisting of a high frequency weak heart beat motion (about 0.5-3 Hz) and a low frequency intense respiratory motion (about 0.1-1 Hz), and the differential operation contained in the optical flow helps to amplify the weak motion of the heart, but attenuates the respiratory motion at low frequencies. Therefore, when trend and amplitude normalization are not performed on the Camera-SCG signals, the Camera-SCG signals are integrated in the time dimension to reconstruct low-frequency respiratory motion signals, and particularly, the cumulative sum of each time point of the Camera-SCG time sequence is calculated. And then positioning the time sequence phase characteristics of the reconstructed respiratory motion and the heart motion, namely setting respiratory motion characteristic points and heartbeat motion characteristic points through a signal separation module, wherein the respiratory motion characteristic points and the heartbeat motion characteristic points respectively represent key signal characteristics in the time sequence phase characteristics of the reconstructed respiratory motion and the heart motion and are respectively used for reflecting signal characteristic data corresponding to the starting time or the ending time of one respiratory motion period and one heartbeat period. For example, one or more of a mitral valve closure (MC) point, an isovolumetric contraction (IVC) point, an aortic valve opening (AO) point, a Rapid Ejection (RE) point, an aortic valve closure (AC) point, a mitral valve opening (MC) point, and a rapid filling (RE) point may be selected as the heart beat motion feature point. The most important respiratory muscle involved in breathing, i.e. the point where the contracted or relaxed state of the diaphragm is most pronounced, is chosen as the respiratory movement characteristic point. The feature points in this embodiment are detected by a peak positioning or machine learning algorithm.
In the same respiratory cycle, in response to detecting the respiratory motion feature points and one or more heartbeat motion feature points, triggering nuclear magnetic resonance scanning to obtain heartbeat image data of images of phases corresponding to each heartbeat motion feature point so as to ensure that clear images are captured in a specific phase of heart motion corresponding to the respiratory motion feature points (such as a certain phase of ventricular contraction or relaxation), reconstructing the heartbeat image data based on time sequence phase features so as to trigger reordering of single-frame magnetic resonance images or multi-frame magnetic resonance images to form continuous and dynamic heart motion images, extracting heart motion signals from the reconstructed heart motion images, and describing motion states of the heart in the whole heart cycle, including contraction and relaxation of heart chamber walls, volume change of heart chambers and the like. And finally, separating the heart motion signal from the composite motion signal to obtain a respiratory motion signal.
The embodiment realizes that a single defocusing Camera is used for simultaneously collecting defocusing interference speckle image sequences of heart motion under the combined action of respiratory motion and heartbeat motion, and extracting a composite motion signal of the heart from the defocusing interference speckle image sequences to be used as a Camera-SCG signal, and the composite gating comprising respiratory motion and cardiac motion triggering is used for successfully separating a low-frequency intense respiratory motion signal and a high-frequency weak heartbeat motion signal contained in the composite motion signal.
For example, the laser is used to irradiate the position of the fourth rib position at the left lower part of the chest of the human body, the defocusing camera is used to shoot a speckle image reflected by the laser, and the periodic composite motion signal of the heart is constructed by analyzing the heart motion state information contained in the laser speckle image, and the waveform chart is normalized, as shown in fig. 7, wherein the trigger point represents the heart motion feature point detected in the same respiratory cycle after the respiratory motion feature point is detected.
As shown in fig. 8, in a preferred embodiment, in response to detecting the temporal phase signature, extracting the cardiac vibration signal and the respiratory motion signal using a preset gating strategy includes:
The method comprises the steps of setting a respiratory motion feature point and a heartbeat motion feature point through a signal separation module, responding to detection of the respiratory motion feature point, triggering nuclear magnetic resonance scanning to obtain heartbeat image data by detecting one or more heartbeat motion feature points in the same respiratory period, namely taking signals of the respiratory motion feature point and the heartbeat motion stage corresponding to each heartbeat motion feature point as starting points (namely heartbeat image data) as gating signals, acquiring the heartbeat image data including phase data of one or more interested motion stages in one heartbeat period and not acquiring phase data of other non-interested motion stages, and obtaining the respiratory motion signal by reconstructing the heartbeat image data based on the time sequence phase features. The specific implementation steps can be referred to the above step S400, and will not be described herein.
As shown in fig. 8, in a preferred embodiment, in response to detecting the temporal phase signature, extracting the cardiac vibration signal and the respiratory motion signal using a preset gating strategy includes:
Setting a respiratory motion feature point and a heartbeat motion feature point, triggering nuclear magnetic resonance to scan an image of the whole heartbeat motion period if the heartbeat motion feature point is detected in the same respiratory period after the respiratory motion feature point is detected, and obtaining heartbeat image data, namely taking signals (namely heartbeat image data) of a heartbeat motion stage corresponding to the respiratory motion feature point and a certain heartbeat motion feature point as starting points as gating signals, wherein the acquired heartbeat image data comprises phase data of a complete heartbeat period, compared with a prospective gating strategy, the radiation dose of a detected person is higher, reconstructing the heartbeat image data based on the time sequence phase feature to obtain a heart motion signal, and obtaining the respiratory motion signal based on the composite motion signal and the heart motion signal. The specific implementation steps can be referred to the above step S400, and will not be described herein.
As shown in fig. 9, corresponding to the magnetic resonance gating method based on the laser speckle image, the embodiment of the invention further provides a magnetic resonance gating device based on the laser speckle image, where the magnetic resonance gating device based on the laser speckle image includes at least one camera and at least one laser lamp, and further includes:
The defocusing speckle image acquisition module 910 is configured to acquire, based on a preset space-time mapping model, a defocusing interference speckle image sequence of the heart irradiated by the laser lamp in a preset time period by using the camera;
the composite motion signal extraction module 920 is configured to obtain a composite motion signal of the heart based on the defocused interference speckle image sequence, where the composite motion signal is formed based on a heart motion and a respiratory motion together;
A temporal phase feature extraction module 930 configured to determine a temporal phase feature of the heart based on the composite motion signal;
the signal separation module 940 is configured to extract a cardiac vibration signal and a respiratory motion signal using a preset gating strategy in response to detecting the timing phase feature.
In particular, in this embodiment, the specific function of the magnetic resonance gating device based on the laser speckle image may also refer to the corresponding description in the magnetic resonance gating method based on the laser speckle image, which is not described herein again.
Based on the above embodiment, the present invention also provides a terminal, and a functional block diagram thereof may be shown in fig. 10. The terminal comprises a processor, a memory, a network interface and a display screen which are connected through a system bus. Wherein the processor of the terminal is adapted to provide computing and control capabilities. The memory of the terminal includes a nonvolatile storage medium, an internal memory. The non-volatile storage medium stores an operating system and a magnetic resonance gating program based on laser speckle images. The internal memory provides an environment for the operation of an operating system and a magnetic resonance gating program based on laser speckle images in a non-volatile storage medium. The network interface of the terminal is used for communicating with an external terminal through a network connection. The magnetic resonance gating program based on the laser speckle images realizes the steps of any one of the magnetic resonance gating methods based on the laser speckle images when being executed by a processor. The display screen of the terminal may be a liquid crystal display screen or an electronic ink display screen.
It will be appreciated by those skilled in the art that the functional block diagram shown in fig. 10 is merely a block diagram of some of the structures associated with the present inventive arrangements and is not limiting of the terminal to which the present inventive arrangements may be applied, and that a particular terminal may include more or less components than those shown, or may combine some of the components, or have a different arrangement of components.
In one embodiment, a terminal is provided, where the terminal includes a memory, a processor, and a magnetic resonance gating program based on laser speckle images stored in the memory and capable of running on the processor, where the magnetic resonance gating program based on laser speckle images implements the steps of any one of the magnetic resonance gating methods based on laser speckle images provided in the embodiments of the present invention when executed by the processor.
The embodiment of the invention also provides a computer readable storage medium, wherein the computer readable storage medium stores a magnetic resonance gating program based on the laser speckle image, and the magnetic resonance gating program based on the laser speckle image realizes any one of the steps of the magnetic resonance gating method based on the laser speckle image provided by the embodiment of the invention when being executed by a processor.
It should be understood that the sequence number of each step in the above embodiment does not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not be construed as limiting the implementation process of the embodiment of the present invention.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions. The functional units and modules in the embodiment may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit, where the integrated units may be implemented in a form of hardware or a form of a software functional unit. In addition, the specific names of the functional units and modules are only for distinguishing from each other, and are not used for limiting the protection scope of the present invention. The specific working process of the units and modules in the above system may refer to the corresponding process in the foregoing method embodiment, which is not described herein again.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the examples described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other manners. For example, the apparatus/terminal device embodiments described above are merely illustrative, e.g., the division of the modules or units described above is merely a logical function division, and may be implemented in other manners, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed.
The embodiments described above are only for illustrating the technical solution of the present invention, but not for limiting the same, and although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solution described in the foregoing embodiments may be modified or some of the technical features may be replaced equally, and that the modifications or replacements are not essential to the corresponding technical solution but are included in the scope of protection of the present invention.
Claims (9)
1. A magnetic resonance gating method based on laser speckle images, characterized by being applied to a magnetic resonance gating device based on laser speckle images, the device comprising at least one camera and at least one laser lamp, comprising the steps of:
Based on a preset space-time mapping model, acquiring a defocused interference speckle image sequence of the heart under the irradiation of the laser lamp in a preset time period by using the camera;
based on the defocusing interference speckle image sequence, obtaining a composite motion signal of the heart, wherein the composite motion signal is formed based on heart motion and respiratory motion together;
Determining a temporal phase characteristic of the heart based on the composite motion signal;
And in response to detecting the time sequence phase characteristic, extracting a heart vibration signal and a respiratory motion signal by using a preset gating strategy.
2. The method of claim 1, wherein the acquiring, with the camera, a sequence of out-of-focus interference speckle images of the heart under the laser light illumination over a predetermined period of time based on a predetermined spatiotemporal mapping model comprises:
Irradiating a preset position of the heart by using the laser lamp based on a preset space-time mapping model;
and acquiring a defocusing interference speckle image sequence of the heart within a preset time period by using the camera.
3. The method of claim 1, wherein the obtaining the composite motion signal of the heart based on the sequence of out-of-focus interferometric speckle images comprises:
Obtaining a defocused speckle signal based on the defocused interference speckle image sequence;
and extracting the out-of-focus speckle signals by using an optical flow algorithm to obtain a composite motion signal of the heart.
4. The method of claim 1, wherein the determining a temporal phase characteristic of the heart based on the composite motion signal comprises:
Dividing the composite motion signal according to the motion phases of the heart, and determining composite motion signal fragments corresponding to each motion phase of the heart;
And extracting features according to the time sequence of the composite motion signal segments corresponding to all the motion phases, and determining the time sequence phase features of the heart.
5. The method of claim 1-4, wherein the extracting cardiac vibration signals and respiratory motion signals using a preset gating strategy in response to detecting the temporal phase signature comprises:
responding to detection of preset respiratory motion feature points and preset heartbeat motion feature points;
When the respiratory motion feature points are detected, triggering nuclear magnetic resonance scanning to obtain heartbeat image data by corresponding phase images of each heartbeat motion feature point if one or more heartbeat motion feature points are detected in the same respiratory period;
Reconstructing the heartbeat image data based on the time sequence phase characteristics to obtain a heart motion signal;
a respiratory motion signal is obtained based on the composite motion signal and the cardiac motion signal.
6. The method of claim 1-4, wherein the extracting cardiac vibration signals and respiratory motion signals using a preset gating strategy in response to detecting the temporal phase signature comprises:
responding to detection of preset respiratory motion feature points and preset heartbeat motion feature points;
when the respiratory motion feature points are detected, triggering nuclear magnetic resonance to scan images of the whole heartbeat motion period if the heartbeat motion feature points are detected in the same respiratory period, and obtaining heartbeat image data;
Reconstructing the heartbeat image data based on the time sequence phase characteristics to obtain a heart motion signal;
a respiratory motion signal is obtained based on the composite motion signal and the cardiac motion signal.
7. A magnetic resonance gating apparatus based on laser speckle images, the apparatus comprising at least one camera and at least one laser light, further comprising:
the defocusing speckle image acquisition module is used for acquiring a defocusing interference speckle image sequence of the heart irradiated by the laser lamp within a preset time period by using the camera based on a preset space-time mapping model;
The compound motion signal extraction module is used for obtaining a compound motion signal of the heart based on the defocusing interference speckle image sequence, and the compound motion signal is formed based on heart motion and respiratory motion together;
a time sequence phase feature extraction module for determining a time sequence phase feature of the heart based on the composite motion signal;
And the signal separation module is used for responding to the detection of the time sequence phase characteristic and extracting a heart vibration signal and a respiratory motion signal by utilizing a preset gating strategy.
8. A terminal comprising a memory, a processor, and a laser speckle image-based magnetic resonance gating program stored on the memory and executable on the processor, which when executed by the processor, implements the steps of the laser speckle image-based magnetic resonance gating method of any one of claims 1-6.
9. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon a magnetic resonance gating program based on laser speckle images, which when executed by a processor, implements the steps of the magnetic resonance gating method based on laser speckle images as claimed in any one of claims 1-6.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106539584A (en) * | 2015-09-22 | 2017-03-29 | 上海联影医疗科技有限公司 | MR imaging method and system |
| US20210146158A1 (en) * | 2018-04-05 | 2021-05-20 | Koninklijke Philips N.V. | Motion tracking in magnetic resonance imaging using radar and a motion detection system |
| CN112996441A (en) * | 2018-06-08 | 2021-06-18 | 数据完整性顾问有限责任公司 | System and method for pulmonary volume gated X-ray imaging |
| US20230062908A1 (en) * | 2021-09-02 | 2023-03-02 | Shanghai United Imaging Healthcare Co., Ltd. | Method and system for magnetic resonance imaging |
| US20240164729A1 (en) * | 2021-01-28 | 2024-05-23 | Koninklijke Philips N.V. | Mri system, in particular a method and system for generating a cardiac trigger signal |
-
2024
- 2024-12-23 CN CN202411897637.5A patent/CN119355608B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106539584A (en) * | 2015-09-22 | 2017-03-29 | 上海联影医疗科技有限公司 | MR imaging method and system |
| US20210146158A1 (en) * | 2018-04-05 | 2021-05-20 | Koninklijke Philips N.V. | Motion tracking in magnetic resonance imaging using radar and a motion detection system |
| CN112996441A (en) * | 2018-06-08 | 2021-06-18 | 数据完整性顾问有限责任公司 | System and method for pulmonary volume gated X-ray imaging |
| US20240164729A1 (en) * | 2021-01-28 | 2024-05-23 | Koninklijke Philips N.V. | Mri system, in particular a method and system for generating a cardiac trigger signal |
| US20230062908A1 (en) * | 2021-09-02 | 2023-03-02 | Shanghai United Imaging Healthcare Co., Ltd. | Method and system for magnetic resonance imaging |
Non-Patent Citations (2)
| Title |
|---|
| WENJIN WANG, ET AL.: "Fundamentals of Camera-PPG Based Magnetic Resonance Imaging", 《IEEE JOURNAL OF BIOMEDICAL AND HEALTH INFORMATICS》, vol. 26, no. 9, 30 September 2022 (2022-09-30), pages 4378 - 4389, XP011919507, DOI: 10.1109/JBHI.2021.3136603 * |
| 李硕 等: "自门控心脏磁共振成像技术的发展与应用", 《中国医学物理学杂志》, vol. 33, no. 11, 30 November 2016 (2016-11-30), pages 1134 - 1143 * |
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| CN119949802A (en) * | 2025-04-03 | 2025-05-09 | 南方科技大学 | MRI real-time triggering method, system, terminal and medium based on SCG-PPG signal |
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