CN118021265B - Blood volume assessment method, device, storage medium and terminal - Google Patents

Abstract

The present invention discloses a blood volume assessment method, device, storage medium and terminal, the method comprising: controlling an imaging device to transmit a signal to a target object that has not been injected with a contrast agent, so as to obtain a first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device; controlling an imaging device to transmit a signal to a target object that has been injected with a contrast agent for a preset duration, so as to obtain a second longitudinal relaxation rate, a first signal intensity and a second signal intensity of a preset tissue signal marker point in the imaging device; calculating the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate; dividing the tension volume and non-tension volume contained in the vascular segment of the target object according to the first signal intensity and the second signal intensity. Therefore, by using the embodiment of the present application, the bleeding volume can be directly calculated, and the accuracy of blood volume assessment is improved.

Description

A blood volume assessment method, device, storage medium and terminal

Technical Field

The present invention relates to the fields of smart medical treatment and computer technology, and in particular to a blood volume assessment method, device, storage medium and terminal.

Background Art

Blood volume assessment plays a critical role in clinical practice and is of great significance for fluid resuscitation, the use of vasoactive drugs, and volume management of patients with kidney disease and heart failure. Intravascular volume is divided into unstressed volume and stressed volume; unstressed volume refers to the volume that fills the blood vessels but does not produce tension on the vascular wall, and stressed volume refers to the volume that produces a pressure difference across the vascular wall. Unstressed volume and stressed volume can be converted into each other. During stress, the smooth muscle of the vascular wall contracts, converting unstressed volume into stressed volume, thereby increasing the amount of blood returning to the heart and cardiac output. Therefore, accurate assessment of blood volume is of great significance.

In related technologies, the relative red blood cell volume is monitored at the end of the artery through optical imaging technology, and the blood volume is indirectly reflected by counting the red blood cells passing through the extremities per unit time. Currently, the amount of unstressed volume reserve in the patient's body can only be reflected indirectly through the amount of volume loss in clinical practice and cannot be directly measured. Stressed volume can only be reflected indirectly by measuring the average systemic filling pressure. Since the indirectly reflected parameters have errors, the accuracy of blood volume assessment is reduced.

Summary of the invention

The embodiments of the present application provide a blood volume assessment method, device, storage medium and terminal. In order to have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. This summary is not a general review, nor is it intended to identify key/important components or describe the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

In a first aspect, an embodiment of the present application provides a blood volume assessment method, the method comprising:

Controlling the imaging device to transmit a signal to a target object that has not been injected with a contrast agent to obtain a first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device;

Controlling the imaging device to transmit a signal to a target object for which the duration of contrast agent injection is a preset duration to obtain a second longitudinal relaxation rate and a first signal intensity of a preset blood pool signal marker point in the imaging device and a second signal intensity of a preset tissue signal marker point;

The total blood volume of the target object is calculated according to the first longitudinal relaxation rate and the second longitudinal relaxation rate; and the tension volume and the untension volume contained in the blood vessel segment of the target object are divided according to the first signal intensity and the second signal intensity.

Optionally, calculating the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate includes:

obtaining longitudinal relaxation characteristics, concentration, and half-life of contrast agents injected into the target subject;

Calculate the product of the longitudinal relaxation characteristic and the concentration to obtain the first parameter;

Calculating the difference between the reciprocal of the second longitudinal relaxation rate and the reciprocal of the first longitudinal relaxation rate to obtain a second parameter;

Calculate the value of the exponential function of the half-life to obtain the third parameter;

The ratio of the first parameter, the second parameter and the third parameter is calculated to obtain the total blood volume of the target object.

Optionally, the total blood volume of the target object is calculated as follows: Vblood = r1*Ca/(1/T1post-1/T1pre)/exp(ln2t/t _1/2 );

Wherein, Vblood is the total blood volume of the target object, r1 is the longitudinal relaxation characteristic of the contrast agent, T1post is the second longitudinal relaxation rate, T1pre is the first longitudinal relaxation rate, exp() is an exponential function, t is the duration of the contrast agent injection into the target object, and t _1/2 is the half-life of the contrast agent.

Optionally, dividing the tension volume and the non-tension volume contained in the blood vessel segment of the target object according to the first signal strength and the second signal strength includes:

Determining whether the current moment reaches the moment of the optimal imaging sequence according to the first signal strength and the second signal strength;

When the current moment reaches the moment of the optimal imaging sequence, acquiring the inversion time of the fast small-angle excitation sequence of the inversion pulse in the imaging device;

Perform imaging scanning on the target object according to the inversion time to obtain a three-dimensional blood vessel image of the target object;

According to the three-dimensional blood vessel image of the target object, the tension volume and the non-tension volume contained in the blood vessel segment of the target object are divided.

Optionally, dividing the tension volume and the non-tension volume contained in the vascular segment of the target object according to the three-dimensional vascular image of the target object includes:

Performing volumetric blood vessel segmentation according to the three-dimensional blood vessel image of the target object to obtain a segmentation template of the target object;

Tracking the blood vessel edge based on the segmentation template of the target object to obtain the center point position of the blood vessel cross section of the target object;

Determine the vascular morphological parameters of the target object according to the center point position of the vascular cross section of the target object, where the vascular morphological parameters include the major axis length and the minor axis length;

The ratio of the short axis length to the long axis length was used as the volumetric vascular morphological variability index of the target object;

According to the volumetric vascular morphological variation index of the target object, the tension volume and non-tension volume contained in the vascular segment of the target object are divided.

Optionally, according to the volumetric vascular morphological variation index of the target object, the tension volume and the untension volume contained in the vascular segment of the target object are divided, including:

When the volumetric vascular morphological variation index of the target object is equal to 1, the vascular segment capacity contained in the voxel of the target object is determined to be the tension capacity and the total volume of the voxel is determined to be the tension volume;

or,

When the volumetric vascular morphological variation index of the target object is less than 1, it is determined that the vascular segment capacity contained in the voxel of the target object is the unstressed capacity and the total volume of the voxel is the unstressed volume.

Optionally, judging whether the current moment reaches the moment of the optimal imaging sequence according to the first signal strength and the second signal strength includes:

Calculating a first ratio of the first signal strength to the second signal strength;

Controlling the imaging device to transmit a signal to a target object for which a contrast agent is injected for a preset time period to obtain a third signal intensity of a preset blood pool signal marker point and a fourth signal intensity of a preset tissue signal marker point in the imaging device;

calculating a second ratio of the third signal strength to the fourth signal strength;

When the difference between the first ratio and the second ratio is within a preset interval, it is determined that the current moment reaches the moment of the optimal imaging sequence.

In a second aspect, an embodiment of the present application provides a blood volume assessment device, the device comprising:

A first control module, used for controlling the imaging device to transmit a signal to a target object that has not been injected with a contrast agent, so as to obtain a first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device;

A second control module is used to control the imaging device to transmit a signal to a target object for which the duration of contrast agent injection is a preset duration, so as to obtain a second longitudinal relaxation rate and a first signal intensity of a preset blood pool signal marker point in the imaging device and a second signal intensity of a preset tissue signal marker point;

The division module is used to calculate the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate; and to divide the tension volume and the untension volume contained in the blood vessel segment of the target object according to the first signal intensity and the second signal intensity.

In a third aspect, an embodiment of the present application provides a computer storage medium, which stores a plurality of instructions, and the instructions are suitable for being loaded by a processor and executing the above-mentioned method steps.

In a fourth aspect, an embodiment of the present application provides a terminal, which may include: a processor and a memory; wherein the memory stores a computer program, and the computer program is suitable for being loaded by the processor and executing the above-mentioned method steps.

The technical solution provided by the embodiments of the present application may have the following beneficial effects:

In an embodiment of the present application, by pre-setting blood pool signal marking points and tissue signal marking points in the imaging device, the marking points can record the longitudinal relaxation rate and signal strength at different scanning times. Therefore, the target object can be scanned before and after the injection of contrast agent, and the parameters reflected by the marking points at different times before and after the injection of contrast agent can be obtained. The bleeding volume can be directly calculated based on the parameters, and the calculated parameters are accurate and reliable, thereby improving the accuracy of blood volume assessment.

It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

FIG1 is a schematic diagram of a flow chart of a blood volume assessment method provided in an embodiment of the present application;

FIG2 is a schematic diagram of a blood vessel imaging provided in an embodiment of the present application;

FIG3 is a schematic diagram of the structure of a blood volume assessment device provided by the present application;

FIG. 4 is a schematic diagram of the structure of a terminal provided in an embodiment of the present application.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them.

It should be clear that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples of devices and methods consistent with some aspects of the present invention as detailed in the attached claims.

In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" refers to two or more. "And/or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character "/" generally indicates that the previously associated objects are in an "or" relationship.

The present application provides a blood volume assessment method, device, storage medium and terminal to solve the problems existing in the above-mentioned related technical problems. In the technical solution provided by the present application, the present application pre-sets blood pool signal marker points and tissue signal marker points in the imaging device, and the marker points can record the longitudinal relaxation rate and signal strength at different scanning times. Therefore, the target object can be scanned before and after the injection of contrast agent, and the parameters reflected by the marker points at different times before and after the injection of contrast agent can be obtained. The bleeding volume can be directly calculated based on the parameters, and the calculated parameters are accurate and reliable, thereby improving the accuracy of blood volume assessment. The following is a detailed description using an exemplary embodiment.

The following will introduce the blood volume assessment method provided by the embodiment of the present application in detail in conjunction with Figures 1 and 2. The method can be implemented by relying on a computer program and can be run on a blood volume assessment device based on the von Neumann system. The computer program can be integrated into an application or run as an independent tool application.

Please refer to Figure 1, which is a flow chart of a blood volume assessment method provided in an embodiment of the present application.

As shown in FIG1 , the method of the embodiment of the present application may include the following steps:

S101, controlling an imaging device to transmit a signal to a target object that has not been injected with a contrast agent, so as to obtain a first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device;

Among them, the imaging device can be an MRA (Magnetic Resonance Angiography) device, which is a medical imaging device that uses magnetic resonance imaging technology to display the vascular structure and hemodynamics of the human body; the signal emitted by the imaging device is a radio frequency signal emitted by an RF (Radio Frequency) coil, which can excite hydrogen nuclei in the human body to generate signals; the contrast agent is a substance used for medical examination and diagnosis, and the preferred contrast agent in this application is superparamagnetic nano-iron oxide. The blood pool signal marker point is pre-set in the imaging device for monitoring the longitudinal relaxation rate and signal strength; the longitudinal relaxation rate refers to the relaxation phenomenon of the medium in the longitudinal direction, and the relaxation rate is an important parameter that describes the response speed of the medium to external effects.

In the embodiment of the present application, magnetic resonance coils are deployed at various parts of the target object. The magnetic resonance coil is a key device used for magnetic resonance imaging and is placed around the body of the target object to generate and receive radio frequency signals to obtain images of internal tissues of the human body.

Specifically, the magnetic resonance coil in the embodiment of the present application is a cascaded wrapped magnetic resonance coil, including multiple sub-coils distributed on different parts of the target object, the multiple sub-coils are electrically connected in sequence, and the multiple sub-coils include at least a head wrapped head and neck coil, a shoulder and chest wrapped body coil, an abdomen and waist wrapped body coil, a thigh and knee joint wrapped body coil, and a calf and foot wrapped body coil.

In some embodiments, first, the whole body of the target object is wrapped with a magnetic resonance coil of an imaging device, specifically, the head is wrapped with a head and neck coil C _head-neck , the shoulders and chest are wrapped with a body coil C _{shoulder-chest} , the abdomen and waist are wrapped with a body coil C _{stomach-waist} , the thigh and knee joint are wrapped with a body coil C _thigh-knee , and the calf and foot are wrapped with a body coil C _shank-foot . The above coil types and part sequences are examples, but are not limited to the above part wrapping sequences and settings; then, the connecting coil C _link is used to respectively connect C _head-neck and C _{shoulder-chest} , connect C _{shoulder-chest} and C _{stomach-waist} , connect C _{stomach-waist} and C _thigh-knee , and connect C _thigh-knee and C _shank-foot . The above are examples of the connection sequence between the parts, and the actual scenario is not limited to the above connection sequence.

After the magnetic resonance coil of the imaging device is deployed on the target object, the monitoring mark point L _b and the tissue signal mark point _LT can be set in the imaging device D, wherein the optimal position of L _b is the right ventricle, wherein the optimal position of L _t is the interventricular septum, but is not limited to the optimal position; then, a multimodal imaging sequence S is set in the imaging device D, and the imaging sequence S is a rapid small-angle excitation sequence with a preset reversal pulse, which is a rapid small-angle excitation sequence with reversal pulses (Rapid Small-Angle Excitation Sequences with Reversal Pulses, referred to as RARE), which is a pulse sequence commonly used in nuclear magnetic resonance imaging.

In an embodiment of the present application, before contrast agent is injected into the target object, the computer system of the imaging device first controls the radio frequency coil of the imaging device to transmit a signal to the target object that has not been injected with contrast agent to obtain the first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device.

In some embodiments, the imaging device is started to monitor and record the first longitudinal relaxation rate T _1-pre of the marking point L _b . In this embodiment, T _1-pre is milliseconds.

S102, controlling the imaging device to transmit a signal to the target object for which the contrast agent is injected for a preset time, so as to obtain a second longitudinal relaxation rate and a first signal intensity of a preset blood pool signal marker point in the imaging device and a second signal intensity of a preset tissue signal marker point;

In an embodiment of the present application, after the contrast agent is injected into the target object, the computer system of the imaging device controls the imaging device to transmit a signal to the target object to which the contrast agent has been injected for a preset time period, so as to obtain the second longitudinal relaxation rate of the preset blood pool signal marking point in the imaging device, the first signal intensity and the second signal intensity of the preset tissue signal marking point.

In some embodiments, the blood pool contrast agent concentration _Ca and injection volume _Qa , as well as the injection speed _Va are set, wherein the optimal value of _Ca is 5 mg/mL, the optimal value of _Qa is 3 mg/kg, and the optimal value of _Va is 0.1 mL/s, but they are not limited to the optimal values; secondly, the contrast agent is injected into the vein using, but not limited to, a hand-push or pressure syringe; finally, after the blood pool contrast agent is completely injected into the body for t hours, the imaging device is started again to image any vascular bed, and the second longitudinal relaxation rate T1 _-post and the first signal intensity Xb _-post of the marking point _Lb , as well as the second signal intensity XT _-post of the tissue signal marking point _LT are monitored and recorded; in this embodiment, T1 _-pre = milliseconds, and the contrast agent is injected into the body for 0.5 hours.

The vascular bed refers to a structure composed of a network of blood vessels, which is an important part of the human circulatory system. The vascular bed is generally composed of capillaries, arterioles, venules and other blood vessels, which are interconnected to form a complete network. The vascular bed maintains the body's vital activities by transporting oxygen and nutrients, while removing metabolic products and waste from the body.

S103, calculating the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate; and dividing the tension volume and the untension volume contained in the blood vessel segment of the target object according to the first signal intensity and the second signal intensity.

In an embodiment of the present application, the process of calculating the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate includes: obtaining the longitudinal relaxation characteristics, concentration and half-life of the contrast agent injected by the target object; calculating the product of the longitudinal relaxation characteristics and the concentration to obtain a first parameter; calculating the difference between the reciprocal of the second longitudinal relaxation rate and the reciprocal of the first longitudinal relaxation rate to obtain a second parameter; calculating the value of the exponential function of the half-life to obtain a third parameter; calculating the ratio of the first parameter, the second parameter and the third parameter to obtain the total blood volume of the target object. The total blood volume refers to the total blood volume in a person's body, also known as the whole blood volume, which represents the volume of all blood contained in the human body's circulatory system at a specific time point.

Among them, the half-life of the contrast agent refers to the time it takes to eliminate half of it in the body. Since different contrast agents have different chemical compositions and properties, their half-lives will also be different. For example, gadolinium contrast agents may have a longer half-life, ranging from several hours to several days.

Specifically, the total blood volume of the target object is calculated as follows: Vblood=r1*Ca/(1/T1post-1/T1pre)/exp(ln2t/t _1/2 ); wherein Vblood is the total blood volume of the target object, r1 is the longitudinal relaxation characteristic of the contrast agent, T1post is the second longitudinal relaxation rate, T1pre is the first longitudinal relaxation rate, exp() is an exponential function, t is the duration of time the target object is injected with the contrast agent, and t _1/2 is the half-life of the contrast agent.

In an embodiment of the present application, the process of dividing the tension volume and the non-tension volume contained in the vascular segment of the target object according to the first signal intensity and the second signal intensity includes: judging whether the current moment has reached the time of the optimal imaging sequence according to the first signal intensity and the second signal intensity; when the current moment has reached the time of the optimal imaging sequence, acquiring the inversion time of the fast small-angle excitation sequence of the inversion pulse in the imaging device; performing imaging scanning on the target object according to the inversion time to obtain a three-dimensional vascular image of the target object; and dividing the tension volume and the non-tension volume contained in the vascular segment of the target object according to the three-dimensional vascular image of the target object.

Specifically, the process of determining whether the current moment has reached the moment of the optimal imaging sequence based on the first signal strength and the second signal strength includes: calculating a first ratio of the first signal strength to the second signal strength; controlling the imaging device to transmit a signal to the target object for which the contrast agent is injected for a preset time to obtain a third signal strength of a preset blood pool signal marking point and a fourth signal strength of a preset tissue signal marking point in the imaging device; calculating a second ratio of the third signal strength to the fourth signal strength; and determining that the current moment has reached the moment of the optimal imaging sequence when the difference between the first ratio and the second ratio is within a preset interval.

In some embodiments, the signal intensity ratio _Ra = _Xb-post / _XT-post of the monitoring mark points _Lb and _LT is calculated. When _Ra reaches the maximum value, it indicates that the current moment has reached the optimal imaging sequence. The imaging sequence S inversion time TI at _Ra is preset. In this embodiment, TI = 350 ms; the half-life t1 _/2 = 21 hours.

In an embodiment of the present application, the process of dividing the tension volume and the untension volume contained in the vascular segment of the target object according to the three-dimensional vascular image of the target object includes: performing volumetric vascular segmentation according to the three-dimensional vascular image of the target object to obtain a segmentation template of the target object; performing vascular edge tracking based on the segmentation template of the target object to obtain the center point position of the vascular cross section of the target object; determining the vascular morphological parameters of the target object according to the center point position of the vascular cross section of the target object, the vascular morphological parameters including the long axis length and the short axis length; taking the ratio of the short axis length to the long axis length as the volumetric vascular morphological variation index of the target object; and dividing the tension volume and the untension volume contained in the vascular segment of the target object according to the volumetric vascular morphological variation index of the target object. The three-dimensional vascular image of the target object is shown in FIG2 for example.

In some embodiments, the maximum inversion time TI of the difference between blood pool and tissue signal is taken, for example, TI=350ms, the imaging device starts scanning, and after the scanning is completed, a three-dimensional blood vessel image V _vessel is reconstructed; based on the three-dimensional V _vessel , the volumetric vessel segmentation is performed to obtain a segmentation template V _mask ; in this example, the inferior vena cava is selected, and a threshold segmentation method is used, but it is not limited to this method, and other automated or semi-automated work can also be used to extract and segment; based on V _mask , the blood vessel edge is tracked; in this example, a manual delineation method is used, but it is not limited to this method, and other automated or semi-automated work can also be used to track; the position O of the center point of the obtained blood vessel cross section is obtained by blood vessel edge tracking, and the morphological parameters are confirmed according to the position O: the major axis length b and the minor axis length a, and the volumetric vessel morphological variation index CV=a/b is calculated.

In an embodiment of the present application, in the process of dividing the tension volume and non-tension volume contained in the vascular segment of the target object according to the volume vascular morphological variability index of the target object, it includes: when the volume vascular morphological variability index of the target object is equal to 1, determining that the vascular segment volume contained in the voxel of the target object is tension volume and the total volume of the voxel is tension volume; or, when the volume vascular morphological variability index of the target object is less than 1, determining that the vascular segment volume contained in the voxel of the target object is non-tension volume and the total volume of the voxel is non-tension volume.

In some embodiments, for example, CV is used to distinguish the tension capacity and non-tension capacity contained in the vascular segment. When a/b=1, the vascular segment capacity contained in the voxel is the tension capacity, and the total volume of the voxels with a/b=1 is the tension volume; when a/b<1, the vascular segment capacity contained in the voxel is the non-tension capacity, and the total volume of the voxels with a/b<1 is the non-tension volume.

In the embodiment of the present application, the blood volume assessment device first controls the imaging device to transmit a signal to the target object that has not been injected with contrast agent to obtain the first longitudinal relaxation rate of the preset blood pool signal mark point in the imaging device, and then controls the imaging device to transmit a signal to the target object that has been injected with contrast agent for a preset time to obtain the second longitudinal relaxation rate, the first signal intensity and the second signal intensity of the preset tissue signal mark point in the imaging device, and finally calculates the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate, and divides the tension volume and the untension volume contained in the vascular segment of the target object according to the first signal intensity and the second signal intensity. By presetting the blood pool signal mark point and the tissue signal mark point in the imaging device, the mark point can record the longitudinal relaxation rate and signal intensity at different scanning times, so the target object can be scanned before and after the contrast agent is injected, and the parameters reflected by the mark point at different times before and after the contrast agent is injected can be obtained. The bleeding volume can be directly calculated based on the parameters, and the calculated parameters are accurate and reliable, thereby improving the accuracy of blood volume assessment.

The following are embodiments of the apparatus of the present invention, which can be used to implement the embodiments of the method of the present invention. For details not disclosed in the embodiments of the apparatus of the present invention, please refer to the embodiments of the method of the present invention.

Please refer to FIG3, which shows a schematic diagram of the structure of a blood volume assessment device provided by an exemplary embodiment of the present invention. The blood volume assessment device can be implemented as all or part of a terminal through software, hardware, or a combination of both. The device 1 includes a first control module 10, a second control module 20, and a blood vessel division module 30.

A first control module 10 is used to control the imaging device to transmit a signal to a target object that has not been injected with a contrast agent, so as to obtain a first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device;

A second control module 20, for controlling the imaging device to transmit a signal to a target object for which the duration of contrast agent injection is a preset duration, so as to obtain a second longitudinal relaxation rate and a first signal intensity of a preset blood pool signal marker point in the imaging device and a second signal intensity of a preset tissue signal marker point;

The division module 30 is used to calculate the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate; and to divide the tension volume and the untension volume contained in the blood vessel segment of the target object according to the first signal intensity and the second signal intensity.

It should be noted that the blood volume assessment device provided in the above embodiment only uses the division of the above functional modules as an example when executing the blood volume assessment method. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the blood volume assessment device provided in the above embodiment and the blood volume assessment method embodiment belong to the same concept, and the implementation process thereof is detailed in the method embodiment, which will not be repeated here.

The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

In the embodiment of the present application, the blood volume assessment device first controls the imaging device to transmit a signal to the target object that has not been injected with contrast agent to obtain the first longitudinal relaxation rate of the preset blood pool signal mark point in the imaging device, and then controls the imaging device to transmit a signal to the target object that has been injected with contrast agent for a preset time to obtain the second longitudinal relaxation rate, the first signal intensity and the second signal intensity of the preset tissue signal mark point in the imaging device, and finally calculates the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate, and divides the tension volume and the untension volume contained in the vascular segment of the target object according to the first signal intensity and the second signal intensity. By presetting the blood pool signal mark point and the tissue signal mark point in the imaging device, the mark point can record the longitudinal relaxation rate and signal intensity at different scanning times, so the target object can be scanned before and after the contrast agent is injected, and the parameters reflected by the mark point at different times before and after the contrast agent is injected can be obtained. The bleeding volume can be directly calculated based on the parameters, and the calculated parameters are accurate and reliable, thereby improving the accuracy of blood volume assessment.

The present invention also provides a computer-readable medium having program instructions stored thereon, and when the program instructions are executed by a processor, the blood volume assessment methods provided by the above-mentioned various method embodiments are implemented.

The present invention also provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the blood volume assessment method of each of the above method embodiments.

Please refer to FIG4 , which is a schematic diagram of the structure of a terminal provided in an embodiment of the present application. As shown in FIG4 , the terminal 1000 may include: at least one processor 1001 , at least one network interface 1004 , a user interface 1003 , a memory 1005 , and at least one communication bus 1002 .

The communication bus 1002 is used to realize the connection and communication between these components.

The user interface 1003 may include a display screen (Display) and a camera (Camera), and the optional user interface 1003 may also include a standard wired interface and a wireless interface.

The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a WI-FI interface).

Among them, the processor 1001 may include one or more processing cores. The processor 1001 uses various interfaces and lines to connect various parts within the entire electronic device 1000, and executes various functions and processes data of the electronic device 1000 by running or executing instructions, programs, code sets or instruction sets stored in the memory 1005, and calling data stored in the memory 1005. Optionally, the processor 1001 can be implemented in at least one hardware form of digital signal processing (Digital Signal Processing, DSP), field programmable gate array (Field-Programmable Gate Array, FPGA), and programmable logic array (Programmable Logic Array, PLA). The processor 1001 can integrate one or a combination of a central processing unit (Central Processing Unit, CPU), a graphics processing unit (Graphics Processing Unit, GPU) and a modem. Among them, the CPU mainly processes the operating system, user interface and application programs; the GPU is responsible for rendering and drawing the content to be displayed on the display screen; the modem is used to process wireless communications. It can be understood that the above-mentioned modem may not be integrated into the processor 1001, and it can be implemented separately through a chip.

Among them, the memory 1005 may include a random access memory (RAM) or a read-only memory (Read-Only Memory). Optionally, the memory 1005 includes a non-transitory computer-readable storage medium. The memory 1005 can be used to store instructions, programs, codes, code sets or instruction sets. The memory 1005 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data involved in the above-mentioned various method embodiments, etc. The memory 1005 may also be at least one storage device located away from the aforementioned processor 1001. As shown in Figure 4, the memory 1005 as a computer storage medium may include an operating system, a network communication module, a user interface module, and a blood volume assessment application.

In the terminal 1000 shown in FIG4 , the user interface 1003 is mainly used to provide an input interface for the user and obtain data input by the user; and the processor 1001 can be used to call the blood volume assessment application stored in the memory 1005 and specifically perform the following operations:

Controlling the imaging device to transmit a signal to a target object that has not been injected with a contrast agent to obtain a first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device;

Controlling the imaging device to transmit a signal to a target object for which the duration of contrast agent injection is a preset duration to obtain a second longitudinal relaxation rate and a first signal intensity of a preset blood pool signal marker point in the imaging device and a second signal intensity of a preset tissue signal marker point;

The total blood volume of the target object is calculated according to the first longitudinal relaxation rate and the second longitudinal relaxation rate; and the tension volume and the untension volume contained in the blood vessel segment of the target object are divided according to the first signal intensity and the second signal intensity.

In one embodiment, when the processor 1001 calculates the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate, the processor 1001 specifically performs the following operations:

obtaining longitudinal relaxation characteristics, concentration, and half-life of contrast agents injected into the target subject;

Calculate the product of the longitudinal relaxation characteristic and the concentration to obtain the first parameter;

Calculating the difference between the reciprocal of the second longitudinal relaxation rate and the reciprocal of the first longitudinal relaxation rate to obtain a second parameter;

Calculate the value of the exponential function of the half-life to obtain the third parameter;

The ratio of the first parameter, the second parameter and the third parameter is calculated to obtain the total blood volume of the target object.

In one embodiment, when the processor 1001 divides the tension volume and the untension volume contained in the blood vessel segment of the target object according to the first signal strength and the second signal strength, the processor 1001 specifically performs the following operations:

Determining whether the current moment reaches the moment of the optimal imaging sequence according to the first signal strength and the second signal strength;

When the current moment reaches the moment of the optimal imaging sequence, acquiring the inversion time of the fast small-angle excitation sequence of the inversion pulse in the imaging device;

Perform imaging scanning on the target object according to the inversion time to obtain a three-dimensional blood vessel image of the target object;

According to the three-dimensional blood vessel image of the target object, the tension volume and the non-tension volume contained in the blood vessel segment of the target object are divided.

In one embodiment, when the processor 1001 divides the tension volume and the untension volume contained in the vascular segment of the target object according to the three-dimensional vascular image of the target object, the processor 1001 specifically performs the following operations:

Performing volumetric blood vessel segmentation according to the three-dimensional blood vessel image of the target object to obtain a segmentation template of the target object;

Tracking the blood vessel edge based on the segmentation template of the target object to obtain the center point position of the blood vessel cross section of the target object;

Determine the vascular morphological parameters of the target object according to the center point position of the vascular cross section of the target object, where the vascular morphological parameters include the major axis length and the minor axis length;

The ratio of the short axis length to the long axis length was used as the volumetric vascular morphological variability index of the target object;

According to the volumetric vascular morphological variation index of the target object, the tension volume and non-tension volume contained in the vascular segment of the target object are divided.

In one embodiment, when the processor 1001 divides the tension volume and untension volume contained in the vascular segment of the target object according to the volumetric vascular morphological variation index of the target object, the processor 1001 specifically performs the following operations:

When the volumetric vascular morphological variation index of the target object is equal to 1, the vascular segment capacity contained in the voxel of the target object is determined to be the tension capacity and the total volume of the voxel is determined to be the tension volume;

or,

When the volumetric vascular morphological variation index of the target object is less than 1, it is determined that the vascular segment capacity contained in the voxel of the target object is the unstressed capacity and the total volume of the voxel is the unstressed volume.

In one embodiment, when the processor 1001 determines whether the current moment reaches the moment of the optimal imaging sequence according to the first signal strength and the second signal strength, the processor 1001 specifically performs the following operations:

Calculating a first ratio of the first signal strength to the second signal strength;

Controlling the imaging device to transmit a signal to a target object for which a contrast agent is injected for a preset time period to obtain a third signal intensity of a preset blood pool signal marker point and a fourth signal intensity of a preset tissue signal marker point in the imaging device;

calculating a second ratio of the third signal strength to the fourth signal strength;

When the difference between the first ratio and the second ratio is within a preset interval, it is determined that the current moment reaches the moment of the optimal imaging sequence.

In the embodiment of the present application, the blood volume assessment device first controls the imaging device to transmit a signal to the target object that has not been injected with contrast agent to obtain the first longitudinal relaxation rate of the preset blood pool signal mark point in the imaging device, and then controls the imaging device to transmit a signal to the target object that has been injected with contrast agent for a preset time to obtain the second longitudinal relaxation rate, the first signal intensity and the second signal intensity of the preset tissue signal mark point in the imaging device, and finally calculates the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate, and divides the tension volume and the untension volume contained in the vascular segment of the target object according to the first signal intensity and the second signal intensity. By presetting the blood pool signal mark point and the tissue signal mark point in the imaging device, the mark point can record the longitudinal relaxation rate and signal intensity at different scanning times, so the target object can be scanned before and after the contrast agent is injected, and the parameters reflected by the mark point at different times before and after the contrast agent is injected can be obtained. The bleeding volume can be directly calculated based on the parameters, and the calculated parameters are accurate and reliable, thereby improving the accuracy of blood volume assessment.

A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the blood volume assessment program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes in the above-mentioned embodiments of the methods. The storage medium can be a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims (8)

1. A blood volume assessment method, characterized in that the method comprises: Controlling an imaging device to transmit a signal to a target object that has not been injected with a contrast agent, so as to obtain a first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device; Controlling the imaging device to transmit a signal to the target object for which the duration of contrast agent injection is a preset duration, so as to obtain a second longitudinal relaxation rate and a first signal intensity of a preset blood pool signal marker point in the imaging device and a second signal intensity of a preset tissue signal marker point; The total blood volume of the target object is calculated according to the first longitudinal relaxation rate and the second longitudinal relaxation rate; and the tension volume and non-tension volume contained in the blood vessel segment of the target object are divided according to the first signal intensity and the second signal intensity; wherein, Calculating the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate includes: Obtaining the longitudinal relaxation characteristics, concentration and half-life of the contrast agent injected into the target object; Calculating the product of the longitudinal relaxation characteristic and the concentration to obtain a first parameter; Calculating a difference between the reciprocal of the second longitudinal relaxation rate and the reciprocal of the first longitudinal relaxation rate to obtain a second parameter; Calculating the value of the exponential function of the half-life to obtain a third parameter; Calculating the ratio of the first parameter, the second parameter and the third parameter to obtain the total blood volume of the target object; wherein, The dividing the tension volume and the non-tension volume contained in the blood vessel segment of the target object according to the first signal strength and the second signal strength includes: determining whether the current moment reaches the moment of the optimal imaging sequence according to the first signal strength and the second signal strength; When the current moment reaches the moment of the optimal imaging sequence, acquiring the inversion time of the fast small-angle excitation sequence of the inversion pulse in the imaging device; Performing imaging scanning on the target object according to the inversion time to obtain a three-dimensional blood vessel image of the target object; According to the three-dimensional blood vessel image of the target object, the tension volume and the non-tension volume contained in the blood vessel segment of the target object are divided. 2. The method according to claim 1, characterized in that the total blood volume of the target object is calculated by the formula: in, is the total blood volume of the target object, is the longitudinal relaxation property of the contrast agent, is the second longitudinal relaxation rate, is the first longitudinal relaxation rate, is an exponential function, the duration of time during which the contrast agent is injected into the target object, is the half-life of the contrast agent, is the blood pool contrast agent concentration. 3. The method according to claim 1, characterized in that said dividing the tension volume and the non-tension volume contained in the vascular segment of the target object according to the three-dimensional vascular image of the target object comprises: Performing volumetric blood vessel segmentation according to the three-dimensional blood vessel image of the target object to obtain a segmentation template of the target object; Tracking the edge of the blood vessel based on the segmentation template of the target object to obtain the center point position of the blood vessel cross section of the target object; Determining the vascular morphological parameters of the target object according to the center point position of the vascular cross section of the target object, wherein the vascular morphological parameters include the major axis length and the minor axis length; Using the ratio of the short axis length to the long axis length as the capacitive vascular morphological variation index of the target object; According to the volumetric vascular morphological variation index of the target object, the tension volume and the untension volume contained in the vascular segment of the target object are divided. 4. The method according to claim 3, characterized in that the step of dividing the tension volume and the untension volume contained in the vascular segment of the target object according to the volume vascular morphological variation index of the target object comprises: When the volumetric vascular morphological variation index of the target object is equal to 1, determining that the vascular segment capacity contained in the voxel of the target object is the tension capacity and the total volume of the voxel is the tension volume; or, When the volumetric vascular morphological variation index of the target object is less than 1, it is determined that the vascular segment capacity contained in the voxel of the target object is the untensioned capacity and the total volume of the voxel is the untensioned volume. 5. The method according to claim 1, characterized in that the step of determining whether the current moment has reached the moment of the optimal imaging sequence according to the first signal strength and the second signal strength comprises: Calculating a first ratio of the first signal strength to the second signal strength; Controlling the imaging device to transmit a signal to the target object for which the duration of contrast agent injection is a preset duration, so as to obtain a third signal intensity of a preset blood pool signal marking point and a fourth signal intensity of a preset tissue signal marking point in the imaging device; Calculating a second ratio of the third signal strength to the fourth signal strength; When the difference between the first ratio and the second ratio is within a preset interval, it is determined that the current moment reaches the moment of the optimal imaging sequence. 6. A blood volume assessment device, characterized in that the device comprises: A first control module, used for controlling the imaging device to transmit a signal to a target object that has not been injected with a contrast agent, so as to obtain a first longitudinal relaxation rate of a preset blood pool signal marker point in the imaging device; A second control module is used to control the imaging device to transmit a signal to the target object for which the contrast agent is injected for a preset time period, so as to obtain a second longitudinal relaxation rate and a first signal intensity of a preset blood pool signal marker point in the imaging device and a second signal intensity of a preset tissue signal marker point; A division module is used to calculate the total blood volume of the target object according to the first longitudinal relaxation rate and the second longitudinal relaxation rate; and to divide the tension volume and non-tension volume contained in the blood vessel segment of the target object according to the first signal intensity and the second signal intensity; wherein, The division module is specifically used for: Obtaining the longitudinal relaxation characteristics, concentration and half-life of the contrast agent injected into the target object; Calculating the product of the longitudinal relaxation characteristic and the concentration to obtain a first parameter; Calculating a difference between the reciprocal of the second longitudinal relaxation rate and the reciprocal of the first longitudinal relaxation rate to obtain a second parameter; Calculating the value of the exponential function of the half-life to obtain a third parameter; Calculating the ratio of the first parameter, the second parameter and the third parameter to obtain the total blood volume of the target object; wherein, The division module is specifically used for: determining whether the current moment reaches the moment of the optimal imaging sequence according to the first signal strength and the second signal strength; When the current moment reaches the moment of the optimal imaging sequence, acquiring the inversion time of the fast small-angle excitation sequence of the inversion pulse in the imaging device; Performing imaging scanning on the target object according to the inversion time to obtain a three-dimensional blood vessel image of the target object; According to the three-dimensional blood vessel image of the target object, the tension volume and the non-tension volume contained in the blood vessel segment of the target object are divided. 7. A computer storage medium, characterized in that the computer storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor and executing the method according to any one of claims 1 to 5. 8. A terminal, comprising: a processor and a memory; wherein the memory stores a computer program, and the computer program is suitable for being loaded by the processor and executing the method according to any one of claims 1 to 5.