1. The utility model provides a laser ablation evaluation system based on magnetic resonance guide which characterized in that, includes and predicts module, monitoring module and evaluation module, wherein:

the estimation module is used for processing at least one of the following steps: creating a planned ablation area, finishing the pre-estimation of the planned ablation area and planned ablation parameters and obtaining a surgical plan;

the monitoring module monitors the ablation process in real time;

the evaluation module reconstructs an actual ablation region, and performs comparative analysis on the images of the planned ablation region and the actual ablation region to obtain image evaluation information, and the image evaluation information is displayed on the human-computer interaction module; the image evaluation information at least comprises one of the following: percent ablated area, tissue shrinkage, tissue bulking, tissue edema.

2. The system of claim 1, wherein the estimation module estimates the planned ablation parameters based on the planned ablation area and the surgical plan by a fitting function, the fitting function being expressed as a function of ablation time and ablation area at a predetermined laser power and laser wavelength, according to the formula:

wherein, area (t) is a piecewise function for representing the ablation area at the ablation time t; c₀Is a first constant, C₁Is a second constant, C₂Is a third constant, C₃Is a fourth constant, wherein C₀、C₁、C₂、C₃Is a constant acquired in advance; t is ablationTime; c_maxThe maximum ablation area; y is the time at which the fitting function linearly increases the end point; z is the time at which the maximum ablation area is achieved.

3. A magnetic resonance guidance-based laser ablation assessment system according to claim 2, wherein said fitting function is obtained by:

acquiring a plurality of groups of actual ablation experimental data, wherein the actual ablation experimental data comprise laser light emitting power, ablation time, ablation area, laser wavelength and total energy;

and fitting the actual ablation experimental data to obtain the fitting function.

4. A system as claimed in claim 1, wherein the estimation module is configured to perform at least the following:

firstly, acquiring a medical image of focus tissues;

secondly, confirming the tissue type and the tissue attribute of the lesion tissue;

obtaining a three-dimensional model of the lesion tissue according to the medical image, wherein the three-dimensional model is attached with the tissue type and the tissue attribute;

fourthly, according to the three-dimensional model, different tissue types of the lesion tissues are segmented and divided into a plurality of segmentation areas capable of three-dimensional display;

and fifthly, simulating dynamic temperature distribution and/or ablation damage condition percentage distribution map of the actual ablation process based on the tissue attribute of each segmentation region so as to determine the operation scheme of the whole three-dimensional model.

5. The magnetic resonance guidance-based laser ablation evaluation system according to claim 4, wherein the estimation module at least considers a biological heat transfer model and/or an energy simulation model containing blood flow perfusion influence to simulate a temperature distribution and/or an ablation damage condition percentage distribution map of an actual ablation process dynamic; and/or the thermal ablation computational model is an arrhenius equation or a CEM43 model.

6. A magnetic resonance guidance-based laser ablation assessment system according to claim 4, wherein said surgical plan includes at least one of: a fiber insertion path, a planned ablation number, the planned ablation region, the planned ablation area, and the planned ablation parameters; and/or

The ablation parameters include at least one of: the light emitting power of the laser, the light emitting time of the laser, the light emitting mode of the laser, the circulation rate of a cooling medium, the wavelength of the laser and the total energy; and/or

The organization attribute comprises at least one of: tissue anisotropy, tissue absorption, tissue reflectance, tissue refractive index, tissue perfusion rate, tissue thermal conductivity, tissue specific heat, and tissue heat transfer.

7. The magnetic resonance guidance-based laser ablation evaluation system according to claim 5, wherein the arrhenius equation reflects an empirical formula of a chemical reaction rate with temperature variation, specifically:

wherein the arrhenius equation is used for intraoperative real-time ablation feedback, R is a universal gas constant, T: for temperature (k), A is the Allnius constant in s^-1，E_aIs activation energy, c (0) is the initial concentration of cells, and c (t) is the concentration of cells at time t.

8. The system of any one of claims 1 to 7, wherein the real-time monitoring process of the monitoring module comprises: inserting an ablation probe into a corresponding location according to the surgical plan and the three-dimensional model; setting scanning parameters of magnetic resonance temperature imaging, wherein the monitoring module identifies the size of pixel points by reading information in DICOM images and uses each pixel point as an ablation unit for calculation; and carrying out ablation monitoring by combining the segmentation of the planned ablation region and the tissue attribute under the magnetic resonance temperature measurement.

9. The system of claim 8, wherein an ablation threshold display is performed on the ablation condition of the ablation unit during the ablation monitoring using the arrhenius equation; selecting different colors to mark and display the ablation condition of the ablation unit;

alternatively, ablation threshold displays are made for ablation regions using different colors when the ablation monitoring is made using the CEM43 model.

10. A system as claimed in claim 9, wherein when the ablation monitoring is performed using the arrhenius model, the ablation threshold is displayed for the tissue in the first range when the tissue temperature is outside a first range between likely damage and not completely damaged.

11. A system as claimed in claim 9, wherein the ablation region is displayed as a mask or semi-transparent during the ablation monitoring using the CEM43 model, and the planned and actual ablation regions are viewed simultaneously after the ablation region is overlaid to display the tissue structure phase.

12. A system for assessing laser ablation based on magnetic resonance guidance as claimed in claim 8, wherein if the actual ablation area is larger than the planned ablation area, the monitoring module will automatically prompt a pop-up box to indicate whether to stop ablation; if the actual ablation area exceeds a first percentage, the monitoring module will automatically turn off energy output.

13. A magnetic resonance guidance-based laser ablation assessment system according to claim 8, wherein said assessment module assessing a degree of ablation comprises: highlighting and marking the changed ablation region by using a contrast method, reconstructing a postoperative actual ablation region by using a three-dimensional rapid drawing method, and comparing and calculating the percentage of the ablation area of the actual ablation region with that of the planned ablation region; ablating excessively if the ablation area percentage exceeds a first percentage; under-ablating if below a second percentage, wherein the first percentage is greater than the second percentage.

14. A system as claimed in claim 13, wherein the calculation of the ablation area percentage takes into account at least one of the following factors: an ablation range in which the planned ablation regions are overlapped, an ablation range outside the planned ablation regions, and a range within the planned ablation regions that is not ablated.

Background

With the improvement of living standard and the increase of the whole life span, based on different statistical data, the incidence rate of malignant tumor or tissue lesion can be found to be rapidly increased. The thermal ablation has better curative effect and definite mechanism in the aspects of treating tissue lesion, epilepsy, hamartoma, canceration cell damage and the like, and can accurately ablate single or multiple specific focuses to ensure that the lesion cells generate irreversible damage or coagulation necrosis. In the medical field, there are many ways of thermal ablation, such as radio frequency ablation, microwave ablation, laser ablation, etc. Broadly speaking, high intensity focused ultrasound and cryoablation may also fall within this technology scope.

Typically, the ablation results are evaluated computationally based on lesion tissue temperature and temperature duration to evaluate heat loss from the tissue. In the existing ablation, the greatest limitation is that the ablation region cannot be judged clearly and in real time, the parameters and the ablation area required in the operation process cannot be effectively estimated, and the judgment can be carried out only according to the use experience of related workers. In addition, the main method of the existing ablation is to use CT or perform magnetic resonance for postoperative evaluation after the ablation is completed, if the ablation is not complete, the ablation operation needs to be performed again, which cannot be adjusted in real time during the operation, and under the condition of ensuring complete ablation, excessive ablation may be caused, which may cause irreversible damage to the normal tissues of the patient. With the development of MRI temperature measurement technology, especially in laser ablation, the temperature of tissue is monitored in real time by using MRI, so that the approximate judgment of temperature distribution in the operation is solved, and the ablation result is judged by an ablation formula. However, most ablation formulas are subjected to data correction, and the corrected ablation formulas often introduce clinical experience of related workers, so that the uncertainty of ablation judgment results is increased. Meanwhile, the judgment of the ablation result is only carried out in the operation, and the judgment factor of the tissue ablation condition is single.

The technical staff in the field are faced with a need to solve the problems of how to monitor the ablation result in the whole process, how to accurately evaluate the ablation result based on accurate temperature, and avoiding using uncertain factors such as artificial experience data in the ablation process.

Disclosure of Invention

The embodiment of the specification aims to provide a laser ablation evaluation system based on magnetic resonance guidance, which can perform parameterized ablation prediction, noninvasive real-time damage evaluation and postoperative image confirmation in three time periods before, during and after an operation, so as to perform more accurate thermal ablation on a focus. Meanwhile, the real-time ablation related calculation runs through the whole operation process, so that the operation is more controllable.

To solve the above technical problem, the embodiments of the present specification are implemented as follows.

The invention discloses a laser ablation evaluation system based on magnetic resonance guidance, which comprises an estimation module, a monitoring module and an evaluation module, wherein: the estimation module is used for processing at least one of the following steps: creating a planned ablation area, finishing the pre-estimation of the planned ablation area and planned ablation parameters and obtaining a surgical plan; the monitoring module monitors the ablation process in real time; the evaluation module reconstructs an actual ablation region, and performs comparative analysis on the images of the planned ablation region and the actual ablation region to obtain image evaluation information, and the image evaluation information is displayed on the human-computer interaction module; the image evaluation information at least comprises one of the following: percent ablated area, tissue shrinkage, tissue bulking, tissue edema.

Further, the estimation module estimates the planned ablation parameters through a fitting function based on the planned ablation area and the surgical plan, wherein the fitting function is expressed as a function of the ablation time and the ablation area under the preset laser power and laser wavelength, and the formula is as follows:

wherein, area (t) is a piecewise function for representing the ablation area at the ablation time t; c₀Is a first constant, C₁Is a second constant, C₂Is a third constant, C₃Is a fourth constant, wherein C₀、C₁、C₂、C₃Is a constant acquired in advance; t is the ablation time; c_maxThe maximum ablation area; y is the time at which the fitting function linearly increases the end point; z is the time at which the maximum ablation area is achieved.

Further, the fitting function is obtained by: acquiring a plurality of groups of actual ablation experimental data, wherein the actual ablation experimental data comprise laser light emitting power, ablation time, ablation area, laser wavelength and total energy; and fitting the actual ablation experimental data to obtain the fitting function.

Further, the estimation module at least completes the following processes: firstly, acquiring a medical image of focus tissues;

secondly, confirming the tissue type and the tissue attribute of the lesion tissue; obtaining a three-dimensional model of the lesion tissue according to the medical image, wherein the three-dimensional model is attached with the tissue type and the tissue attribute; fourthly, according to the three-dimensional model, different tissue types of the lesion tissues are segmented and divided into a plurality of segmentation areas capable of three-dimensional display; and fifthly, simulating dynamic temperature distribution and/or ablation damage condition percentage distribution map of the actual ablation process based on the tissue attribute of each segmentation region so as to determine the operation scheme of the whole three-dimensional model.

Further, the estimation module at least considers a biological heat transfer model and/or an energy simulation model containing blood flow perfusion influence to simulate the dynamic temperature distribution and/or ablation damage condition percentage distribution map of the actual ablation process; and/or the thermal ablation computational model is an arrhenius equation or a CEM43 model.

Further, the surgical protocol includes at least one of: a fiber insertion path, a planned ablation number, the planned ablation region, the planned ablation area, and the planned ablation parameters; and/or

The ablation parameters include at least one of: the light emitting power of the laser, the light emitting time of the laser, the light emitting mode of the laser, the circulation rate of a cooling medium, the wavelength of the laser and the total energy; and/or

The organization attribute comprises at least one of: tissue anisotropy, tissue absorption, tissue reflectance, tissue refractive index, tissue perfusion rate, tissue thermal conductivity, tissue specific heat, and tissue heat transfer.

Further, the arrhenius equation reflects an empirical formula of the relationship between the chemical reaction rate and the temperature change, and specifically comprises:

wherein the arrhenius equation is used for intraoperative real-time ablation feedback, R is a universal gas constant, T: for temperature (k), A is the Allnius constant in s^-1，E_aIs activation energy, c (0) is the initial concentration of cells, and c (t) is the concentration of cells at time t.

Further, the real-time monitoring process of the monitoring module comprises: inserting an ablation probe into a corresponding location according to the surgical plan and the three-dimensional model; setting scanning parameters of magnetic resonance temperature imaging, wherein the monitoring module identifies the size of pixel points by reading information in DICOM images and uses each pixel point as an ablation unit for calculation; and carrying out ablation monitoring by combining the segmentation of the planned ablation region and the tissue attribute under the magnetic resonance temperature measurement.

Further, when the ablation monitoring is carried out by using the arrhenius equation, displaying an ablation threshold value of the ablation condition of the ablation unit; selecting different colors to mark and display the ablation condition of the ablation unit; alternatively, ablation threshold displays are made for ablation regions using different colors when the ablation monitoring is made using the CEM43 model.

Further, when the ablation monitoring is performed by using the arrhenius model, when the temperature of the tissue exceeds a first range, wherein the ablation condition of the tissue in the first range is between that of the tissue which may cause damage but is not completely damaged, an ablation threshold display is performed on the tissue in the first range.

Further, when the CEM43 model is used for ablation monitoring, the ablation region is displayed as a mask or in a semi-transparent mode, and after the ablation region is overlaid and displayed with a tissue structure phase, the planned ablation region and the actual ablation region are simultaneously seen.

Further, if the actual ablation area is larger than the planned ablation area, the monitoring module automatically provides a bullet box to prompt whether ablation is stopped; if the actual ablation area exceeds a first percentage, the monitoring module will automatically turn off energy output.

Further, the assessment module assessing the degree of ablation comprises: highlighting and marking the changed ablation region by using a contrast method, reconstructing a postoperative actual ablation region by using a three-dimensional rapid drawing method, and comparing and calculating the percentage of the ablation area of the actual ablation region with that of the planned ablation region; ablating excessively if the ablation area percentage exceeds a first percentage; under-ablating if below a second percentage, wherein the first percentage is greater than the second percentage.

Further, the calculation of the ablation area percentage takes into account at least one of the following factors: an ablation range in which the planned ablation regions are overlapped, an ablation range outside the planned ablation regions, and a range within the planned ablation regions that is not ablated.

The present invention has the following advantageous effects.

The invention can effectively perform pre-operation ablation prediction, give proper thermal dose in the operation and perform real-time ablation evaluation, and can compare images before and after the operation (still in the same magnetic resonance chamber) to more accurately judge the ablation effect. If the ablation effect is not good enough, the ablation can be continued without secondary operation. The accurate ablation evaluation of the whole-course real-time monitoring and the real-time feedback of the ablation result in the operation is realized.

The invention can predict the ablation area before operation, and can perform operation with more accurate path planning and less trauma.

The invention can real-timely and non-invasively estimate the ablation in the operation, guide doctors to perform more accurate ablation operation and reduce the influence caused by incomplete ablation or excessive ablation.

The invention can evaluate and compare images after operation, more quickly draw out an ablation area and judge the state of the ablation area. Imaging is generally used as one of the main criteria for determining whether to ablate, excluding tissue biopsies.

The invention creatively provides an evaluation system integrating a pre-estimation module, a monitoring module and an evaluation module, and the system can assist relevant workers in carrying out rapid and accurate diagnosis and prediction.

Drawings

In order to more clearly illustrate the embodiments of the present specification or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments described in the present specification, and for those skilled in the art, other drawings can be obtained according to the drawings without any creative effort.

FIG. 1 is a block diagram of the system of the present invention.

FIG. 2 is a flow chart of the system operation of the present invention.

FIG. 3A is a schematic diagram of a looped optical fiber of the present invention.

Fig. 3B is a schematic view of a dispersion optical fiber according to the present invention.

FIG. 3C is a schematic view of a side-emitting optical fiber according to the present invention.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present specification, the technical solutions in the embodiments of the present specification will be clearly and completely described below with reference to the drawings in the embodiments of the present specification, and it is obvious that the described embodiments are only a part of the embodiments of the present specification, and not all of the embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments in the present specification without any inventive step should fall within the scope of protection of the present specification.

Example one

A laser ablation evaluation system based on magnetic resonance guidance comprises a pre-estimation module, a monitoring module and an evaluation module, wherein: the estimation module is used for processing at least one of the following steps: creating a planned ablation area, finishing the pre-estimation of the planned ablation area and planned ablation parameters and obtaining a surgical plan; the monitoring module monitors the ablation process in real time; the evaluation module reconstructs an actual ablation region, and images of the planned ablation region and the actual ablation region are registered, compared and analyzed to obtain image evaluation information, and the image evaluation information is displayed on the human-computer interaction module; the image evaluation information at least comprises one of the following: percent ablated area, tissue shrinkage, tissue bulking, tissue edema.

Further, the estimation module estimates the planned ablation parameters through a fitting function based on the planned ablation area and the surgical plan, wherein the fitting function is expressed as a function of the ablation time and the ablation area under the preset laser power and laser wavelength, and the formula is as follows:

wherein, area (t) is a piecewise function for representing the ablation area at the ablation time t; c₀Is a first constant, C₁Is a second constant, C₂Is a third constant, C₃Is a fourth constant, wherein C₀、C₁、C₂、C₃Is a constant acquired in advance; t is the ablation time; c_maxThe maximum ablation area; y is the time at which the fitting function linearly increases the end point; z is the time at which the maximum ablation area is achieved.

Wherein the fitting function is obtained by:

acquiring a plurality of groups of actual ablation experimental data, wherein the actual ablation experimental data comprise laser light emitting power, ablation time, ablation area, laser wavelength and total energy; and fitting the actual ablation experimental data to obtain the fitting function. The fitting manner may adopt a piecewise regression manner or other fitting manners, and the fitting manners are all prior art and are not described herein again.

Further, the estimation module at least completes the following processes:

firstly, acquiring a medical image of focus tissues;

secondly, confirming the tissue type and the tissue attribute of the lesion tissue;

obtaining a three-dimensional model of the lesion tissue according to the medical image, wherein the three-dimensional model is attached with the tissue type and the tissue attribute;

fourthly, according to the three-dimensional model, different tissue types of the lesion tissues are segmented and divided into a plurality of segmentation areas capable of three-dimensional display;

and fifthly, simulating the actual ablation process based on the tissue attribute of each segmentation region to obtain a dynamic temperature distribution and/or ablation damage condition percentage distribution map, and acquiring the operation scheme of the whole three-dimensional model.

The estimation module at least adopts a biological heat transfer model and/or an energy simulation model containing blood flow perfusion influence to simulate an actual ablation process to obtain a dynamic temperature distribution and/or ablation damage condition percentage distribution map; and/or the thermal ablation computational model is an Arrhenius equation (Arrhenius' evaluation) or a CEM43 model.

Wherein the surgical protocol comprises at least one of: a fiber insertion path, a planned ablation number, the planned ablation region, the planned ablation area, and the planned ablation parameters; and/or, the ablation parameter comprises at least one of: the light emitting power of the laser, the light emitting time of the laser, the light emitting mode of the laser, the circulation rate of a cooling medium, the wavelength of the laser and the total energy; and/or, the organization attribute comprises at least one of: tissue anisotropy, tissue absorption, tissue reflectance, tissue refractive index, tissue perfusion rate, tissue thermal conductivity, tissue specific heat, tissue heat transfer; and/or, the energy simulation model comprises at least one of the following: monte Carlo simulation model, Maxwell simulation model.

Further, the Arrhenius equation (Arrhenius' equation) reflects an empirical formula of the relationship between the chemical reaction rate and the temperature change, and specifically includes:

wherein the Arrhenius equation (Arrhenius' equalisation) is used for intraoperative real-time ablation feedback, R is a universal gas constant, T: for temperature (k), A is the Arrhenius constant (Arrhenius' constant) in s^-1，E_aIs activation energy, c (0) is the initial concentration of cells, and c (t) is the concentration of cells at time t.

Further, the real-time monitoring process of the monitoring module comprises: inserting an ablation probe into a corresponding location according to the surgical plan and the three-dimensional model; setting scanning parameters of magnetic resonance temperature imaging, wherein the monitoring module automatically identifies the size of pixel points by reading information in DICOM images and uses each pixel point as an ablation unit for calculation; ablation monitoring using the Arrhenius equation (Arrhenius' evaluation) or the CEM43 model at magnetic resonance non-invasive temperature measurement in combination with segmentation of the planned ablation region and the tissue properties.

Wherein, when the Arrhenius equation is used for the ablation monitoring, the ablation threshold value of the ablation condition of the ablation unit is displayed; selecting different colors to mark different ablation conditions of the ablation unit and displaying the marking to be ablation threshold display; alternatively, when the ablation monitoring is performed using the CEM43 model, the ablation regions are displayed with different colors at different equivalent ablation durations of 43 ℃.

For example, in a preferred embodiment of the present invention, the ablation threshold display comprises at least one of: when Ω is 1, the cell damage rate is 63.2%, and the tissue within the ablation threshold range is displayed in a first color, for example, the first color is yellow; when Ω is 4.6, the cell damage rate is 99%, and the tissue within the ablation threshold range is displayed in a second color, for example, red. Further, the relevant worker may preset a first range (the setting of the first range may be freely set according to the operation condition), when the tissue temperature exceeds the first range, for example, the first range is 43 ℃ -50 ℃, the ablation condition of the tissue in the first range is between that of the tissue which may cause damage but is not completely damaged, the ablation threshold of the tissue in the first range is displayed, and the ablation threshold of the tissue is displayed in a third color, for example, the third color is green.

Furthermore, the setting and selection of the first color, the second color and the third color can be freely adjusted according to the preference or ablation condition of the relevant workers. Preferably, the third color can be displayed preferentially on the bottom surface of the ablation region with the color mark, and can also be partially covered by other ablation threshold display regions.

Wherein, when the CEM43 model is used for the ablation monitoring, the ablation area is displayed as a MASK (MASK) or semi-transparent, and the planned ablation area and the actual ablation area can be seen simultaneously after the ablation area is overlaid and displayed with a tissue structure phase.

If the actual ablation area is larger than the planned ablation area, the monitoring module automatically provides a bullet box to prompt whether ablation is stopped; if the actual ablation area exceeds a first percentage, for example the first percentage is set to 110%, the monitoring module will automatically turn off the energy output.

Wherein, the evaluation module evaluates the ablation degree, specifically: highlighting and marking the changed ablation region by using a contrast method, reconstructing a postoperative actual ablation region by using a three-dimensional rapid drawing method, and comparing and calculating the percentage of the ablation area of the actual ablation region with that of the planned ablation region; if the ablation area percentage exceeds a first percentage, e.g., the first percentage is set to 110%, then ablation is considered excessive; if it is below a second percentage, for example 90%, ablation is considered insufficient. Preferably, the first percentage is greater than the second percentage. The first percentage and the second percentage are not unique, and the worker can freely set the percentages according to the operating conditions.

Wherein the calculation of the ablation area percentage takes into account at least one of the following factors: an ablation range in which the planned ablation regions are overlapped, an ablation range outside the planned ablation regions, and a range within the planned ablation regions that is not ablated. Preferably, for example, the calculation method of the ablation percentage adopts boolean operation, which is the prior art and is not described herein again.

Example two

A laser ablation evaluation system based on magnetic resonance guidance comprises a pre-estimation module, a monitoring module and an evaluation module, wherein the pre-estimation module is used for pre-estimating an ablation area and ablation parameters by three-dimensionally sketching an ablation area and a peripheral area, adding corresponding material attributes, storing a tissue material attribute list, and using a fitting function or a simulation energy diffusion model based on a thermal ablation calculation model; the monitoring module carries out real-time monitoring and ablation evaluation on the ablation process; the evaluation module carries out three-dimensional modeling on the ablation region evaluated in real time, automatically fits to an approximate ablation region, or carries out registration and contrast analysis on a preoperative structural phase and a postoperative same sequence image, uses a contrast method to carry out highlight identification on the changed region, uses a three-dimensional rapid drawing method to reconstruct the postoperative ablation region, and compares the postoperative ablation region with the preoperative estimated ablation region.

The functions of the laser ablation evaluation system based on magnetic resonance guidance are realized through corresponding hardware equipment, usually, evaluation system software is loaded in the hardware, and the evaluation system software can assist medical workers in making accurate operation planning and postoperative evaluation and can realize real-time monitoring of the process. The detailed description will be given below by taking the hardware device as a laser interstitial thermotherapy device as an example.

In the second embodiment, the laser interstitial thermotherapy device is loaded with the laser ablation evaluation system based on magnetic resonance guidance, the laser ablation evaluation system at least comprises a prediction module, a monitoring module and an evaluation module, and pre-operation ablation area prediction and parameter prediction, intra-operation real-time ablation monitoring and post-operation ablation image evaluation are realized through the prediction module, the monitoring module and the evaluation module, so that a pre-operation, intra-operation and post-operation three-in-one ablation evaluation scheme is obtained. Compared with the prior art, the laser ablation evaluation system combines the evaluation modes of the three stages of preoperative, intraoperative and postoperative into a whole set of complete ablation evaluation mode, runs through the whole operation process, more accurately assists related workers to carry out preoperative planning and timely monitoring, and effectively judges ablation results; the whole ablation process is parameterized and planned, so that risks caused by accidents are reduced. The details are as follows.

Stage one: preoperative ablation area prediction and parameter prediction

At this stage, the estimation module is to perform at least one of the following: creating a planned ablation area, finishing the estimation of the planned ablation area and the planned ablation parameters, obtaining a surgical plan and the like. More specifically, at least the following will be done: acquiring a medical image of lesion tissues, wherein the medical image comprises but is not limited to a CT image, a magnetic resonance image and a PET image; ② analyzing and confirming the tissue type and tissue attribute of the lesion tissue, for example, the tissue type may include one or more than two, each of the tissue types having its specific tissue attribute. The organization type and the organization attribute list can be extracted and preset in the pre-estimation module, and the organization attribute comprises at least one of the following: tissue anisotropy, tissue absorption, tissue reflectance, tissue refractive index, tissue perfusion rate, tissue thermal conductivity, tissue specific heat, and tissue heat transfer. Thirdly, according to the medical image, a multi-mode fusion technology is adopted to obtain a three-dimensional model of the lesion tissue, namely a planned ablation area is automatically created, and the three-dimensional model is attached with the tissue type and the tissue attribute. Fourthly, according to the three-dimensional model, different tissue types of the lesion tissues are segmented, and finally, the lesion tissues are segmented into a plurality of segmentation areas capable of being displayed in a three-dimensional manner; meanwhile, the focus tissue and the normal tissue around the focus tissue can be segmented. Simulating an actual ablation process based on the tissue attribute of each segmentation region to obtain a dynamic temperature distribution and/or ablation damage condition percentage distribution map, and acquiring an operation scheme of the whole three-dimensional model by combining preoperative software; the surgical protocol includes at least one of: a fiber insertion path, a planned number of ablations, the planned ablation region, the planned ablation area, and the planned ablation parameters.

In the first stage, the tissue type and the tissue attribute of the lesion tissue are confirmed, and then graph segmentation is carried out according to different tissue types, so that the tissue condition of the lesion tissue is clear at a glance, the lesion tissue can be integrally grasped more accurately by related workers, and the obtained surgical plan has higher accuracy and reliability; the inaccuracy caused by manually drawing the focus area or the ablation area in the prior art is avoided.

Further, the estimation module at least adopts a biological heat transfer model and/or an energy simulation model containing blood flow perfusion influence to simulate an actual ablation process to obtain a dynamic temperature distribution and/or ablation damage condition percentage distribution map; and/or the thermal ablation computational model is an arrhenius equation or a CEM43 model.

Further, the energy simulation model comprises at least one of: monte Carlo simulation model, Maxwell simulation model.

Further, in the present invention, the estimation module estimates the planned ablation parameters based on the planned ablation area and the surgical plan by using a fitting function, where the fitting function is expressed as a function of the ablation time and the ablation area at the predetermined laser power and laser wavelength, and the formula is as follows:

wherein, area (t) is a piecewise function for representing the ablation area at the ablation time t; c₀Is a first constant, C₁Is a second constant, C₂Is a third constant, C₃Is a fourth constant, wherein C₀、C₁、C₂、C₃Is a constant acquired in advance; t is the ablation time; c_maxThe maximum ablation area; y is the time at which the fitting function linearly increases the end point; z is the time at which the maximum ablation area is achieved.

More specifically, the estimation module acquires a large amount of actual ablation experimental data, wherein the actual ablation experimental data comprises laser light emitting power, ablation time, ablation area, laser wavelength and total energy; under the condition of different laser light-emitting power and laser wavelength, fitting of ablation time and ablation area is carried out to obtain a fitting function, and the fitting function is used for calculating a planned ablation parameter comprising at least one of the following parameters: the light emitting power of the laser, the light emitting time of the laser, the light emitting mode of the laser, the circulation rate of the cooling medium, the wavelength of the laser and the total energy.

For example, in the second embodiment, based on a large amount of actual ablation experimental data, under a certain light output power, the fitting function of the ablation area of the normal center cross section of the optical fiber and time is linear in the first stage, and then tends to converge under the combined action of the factors such as the blood perfusion and the cooling system, and because of the physical property limit of the 980nm or 1064nm laser, there is a limit of the maximum ablation area, and the limit of the maximum ablation area forms the boundary of the fitting function, so the fitting function is expressed as a three-stage piecewise function, the first stage is a linear increase stage of the ablation area, the second stage is a temperature convergence stage at the same power, and the third stage is a maximum ablation area under the physical property limit, as shown below (first expression method):

wherein, area (t) is a piecewise function for representing the ablation area at the ablation time t; c₀Is a first constant, C₁Is a second constant, C₂Is a third constant, C₃Is a fourth constant, wherein C₀、C₁、C₂、C₃Is a constant acquired in advance; t is the ablation time; c_maxThe maximum ablation area; y is the time at which the fitting function linearly increases the end point; z is the time at which the maximum ablation area is achieved.

As mentioned above, the formula of the area (t) piecewise function is based on a large amount of actual ablation experimental data, which may be laser hyperthermia equipment. Specifically, the relevant worker may perform ablation experiments at a selected laser power, for example, at 3W, or at any laser power between 5W and 20W, or at 23W, 25W, etc., using a ring-shaped fiber or using dispersive fibers with different lengths of light output. And recording experimental data in the experimental process, wherein the experimental data mainly comprises tissue type, tissue characteristics, light emitting power of laser, ablation time, ablation area, laser wavelength, light emitting mode and total energy. Wherein the ablation area is preferentially expressed as a cross section perpendicular to the ablation central region of the optical fiber (i.e. an ablation area on a cross section of a plane normal to the center of the light exit portion of the optical fiber).

That is, if a ring-shaped optical fiber is used, the ablation area represents an ablation area on a cross section of a normal plane on a central point of a light emergent portion of the ring-shaped optical fiber; if a dispersion optical fiber is used, the ablation area represents the ablation area on the cross section of the normal plane on the center point of the light emergent part of the dispersion optical fiber. Furthermore, if the optical fiber used is a side-emitting optical fiber, the dynamic change of the transmission depth achieved by the side-emitting optical fiber can be expressed by adopting an equivalent radius under the condition that the laser wavelength and the light-emitting mode are consistent. Therefore, the area (t) piecewise function of the invention is more suitable for ring fiber and dispersion fiber. Furthermore, the applicability of the area (t) piecewise function also includes the application to a medical ablation fiber assembly with or without a cooling system.

Further, as shown in fig. 3A, a schematic diagram of the ring-shaped optical fiber of the present invention is shown. The ring-shaped optical fiber is a laser transmission optical fiber, and the front end light-emitting mode of the ring-shaped optical fiber is output along the whole circumference of the radial direction. Fig. 3B is a schematic diagram of a dispersive optical fiber according to the present invention. A dispersion fiber is a laser delivery fiber whose front end light exit pattern will be output radially and axially over a predefined length all around. FIG. 3C is a schematic diagram of a side-emitting optical fiber according to the present invention. The side-emitting optical fiber is a laser transmission optical fiber, and the front light emitting mode of the side-emitting optical fiber is output along the radial side surface. The laser thermotherapy device, the annular optical fiber, the dispersion optical fiber, the side-emitting optical fiber, the medical ablation optical fiber assembly and the like are all the existing devices or technologies, and are not described herein any more.

Furthermore, on the basis of a large number of ablation experiments, induction verification is carried out on ablation experiment data, and finally a formula of the area (t) piecewise function is obtained through fitting. The formula of the area (t) piecewise function can also be expressed in the following form (second expression):

wherein, area (t) is a piecewise function for representing the ablation area at the ablation time t; d₀Is a first constant, D₁Is a second constant, wherein D₀、D₁Is a constant acquired in advance; t is the ablation time; d_maxThe maximum ablation area; y is the time at which the fitting function linearly increases the end point; z is the time at which the maximum ablation area is achieved. The second expression method is a variation of the first expression method, and has an advantage in that the fitting function calculation can be simplified by reducing the number of pre-constants to be obtained.

Based on the second expression method, the creator of the invention uses the dispersive optical fiber to perform a large number of ablation experiments on the pork liver under the conditions that the laser power is 6W, the laser wavelength is 980nm and the light is continuously emitted, and records experimental data such as tissue type, tissue characteristics, ablation time, ablation area and the like in real time, and summarizes the data as follows:

wherein area (t) is a piecewise function representing an ablation area/mm at an ablation time t²(square millimeters); t is ablation time/s (seconds).

In the same way, based on a large number of actual ablation experiments, fitting functions of other types of tissues under a certain preset laser power and laser wavelength can be obtained, and more accurate ablation parameters can be further obtained through the fitting functions. Therefore, the estimation module can give corresponding ablation parameters based on different tissue types, compared with the prior art, the method realizes finer and more accurate ablation estimation, enhances the reliability of estimation information, and has more guiding significance.

Stage two, real-time ablation monitoring

Further, the real-time monitoring process of the monitoring module comprises: inserting an ablation probe into a corresponding location according to the surgical plan and the three-dimensional model; setting scanning parameters of magnetic resonance temperature imaging, wherein the monitoring module automatically identifies the size of pixel points by reading information in DICOM images and uses each pixel point as an ablation unit for calculation; ablation monitoring using the Arrhenius equation (Arrhenius' evaluation) or the CEM43 model at magnetic resonance non-invasive temperature measurement in combination with segmentation of the planned ablation region and the tissue properties.

Further, the arrhenius model reflects an empirical formula of the relationship between the chemical reaction rate and the temperature change, and specifically comprises the following steps:

wherein the Arrhenius model is used for intraoperative real-time ablation feedback, R is a universal gas constant, T: for temperature (k), A is the Allnius constant in s^-1，E_aIs activation energy, c (0) is the initial concentration of cells, and c (t) is the concentration of cells at time t.

When the arrhenius equation is used for the ablation monitoring, an ablation threshold value can be displayed for the ablation condition of the ablation unit; wherein different colors are selected to mark and display different ablation conditions of the ablation unit.

For example, in a preferred embodiment of the present invention, when the ablation monitoring is performed using the arrhenius equation, the ablation threshold display comprises at least one of: when Ω is 1, the cell damage rate is 63.2%, and the tissue within the ablation threshold range is displayed in a first color, for example, the first color is yellow; when Ω is 4.6, the cell damage rate is 99%, and the tissue within the ablation threshold range is displayed in a second color, for example, red. Further, the relevant worker may preset a first range (the setting of the first range may be freely set according to actual operating conditions), when the tissue temperature exceeds the first range, for example, the first range is 43 ℃ -50 ℃, the ablation condition of the tissue in the first range is between that of the tissue which may cause damage but is not completely damaged, and the ablation threshold of the tissue is displayed as a third color, for example, the third color is green.

Furthermore, the setting and selection of the first color, the second color and the third color can be freely adjusted according to the preference or ablation condition of the relevant workers. Preferably, the third color can be displayed preferentially on the bottom surface of the ablation region with the color mark, and can also be partially covered by other ablation threshold display regions.

As another example, when the ablation monitoring is performed using the CEM43 model, the ablation regions are displayed with different colors at different equivalent ablation durations of 43 ℃. For example: color distinguishing display is respectively carried out under different conditions of 2 minutes equivalent, 10 minutes equivalent and 60 minutes equivalent, and the color distinguishing display enables doctors to judge the ablation effect better. Additionally, when the ablation monitoring is performed using the CEM43 model, the ablation region is shown as a MASK (MASK) or semi-transparent display, and the planned and actual ablation regions are visible simultaneously after the ablation region is overlaid to display the tissue structure phase. Namely, the ablation area planned before the operation is determined, the actual ablation area during the operation is determined, the ablation coverage area and other conditions are clear at a glance, the operation process is accurate and controllable, related workers are guided to perform more accurate ablation operation, and the influence caused by incomplete ablation or excessive ablation is reduced.

Further, if the actual ablation area is larger than the planned ablation area, the monitoring module automatically provides a bullet box to prompt whether ablation is stopped; if the actual ablation area exceeds a first percentage, for example the first percentage is set to 110%, the monitoring module will automatically turn off the energy output. The first percentage is preset by related workers, and the numerical value of the first percentage can be flexibly set according to actual conditions without limitation.

And a third stage: post-operative ablation image assessment

The assessment module assessing a degree of ablation comprises: highlighting and marking the changed ablation region by using a contrast method, reconstructing a postoperative actual ablation region by using a three-dimensional rapid drawing method, and comparing and calculating the percentage of the ablation area of the actual ablation region with that of the planned ablation region; if the ablation area percentage exceeds a first percentage, e.g., the first percentage is set to 110%, then ablation is considered excessive; if it is below a second percentage, for example 90%, ablation is considered insufficient. Preferably, the first percentage is greater than the second percentage. The first percentage and the second percentage are not exclusive and can be freely set by the worker according to the operating conditions, for example, the first percentage is set to 85% and the second percentage is 54%.

Wherein the percentage of ablated area is calculated taking into account at least one of: an ablation range in which the planned ablation regions are overlapped, an ablation range outside the planned ablation regions, and a range within the planned ablation regions that is not ablated. Preferably, for example, the calculation method of the ablation percentage adopts boolean operation, which is the prior art and is not described herein again.

The evaluation module reconstructs an actual ablation region, and images of the planned ablation region and the actual ablation region are registered, contrasted and analyzed to obtain image evaluation information, and the image evaluation information is displayed on the human-computer interaction module; the image evaluation information at least comprises one of the following: percent ablated area, tissue shrinkage, tissue bulking, tissue edema. Preferably, the tissue shrinkage condition, the tissue expansion condition and the tissue edema condition can be correspondingly marked and displayed on the human-computer interaction module according to requirements. Therefore, the evaluation module can obtain very accurate ablation area evaluation, and can display the shrinkage condition of the tissue, the expansion condition of the tissue and the edema condition of the tissue, so that related workers can more comprehensively know the state of the ablation operation and the ablation area.

Furthermore, the relevant workers can judge whether tissue suction or other operations are needed according to the shrinking condition of the tissue, the swelling condition of the tissue and the edema condition of the tissue. Furthermore, the ablation area in the present invention may also be an ablation volume calculated according to the ablation area, that is, the present invention may use the ablation area for judgment and the ablation volume for judgment during the evaluation. Therefore, the ablation area or the ablation volume according to the present invention can also be expressed as an ablation region, for example, the "if the actual ablation area is larger than the planned ablation area, the monitoring module automatically raises the bullet box to prompt whether to stop ablation" according to the present invention can also be expressed as "if the actual ablation volume is larger than the planned ablation volume, the monitoring module automatically raises the bullet box to prompt whether to stop ablation", or expressed as "if the actual ablation area is larger than the planned ablation area, the monitoring module automatically raises the bullet box to prompt whether to stop ablation". Similarly, when calculating the ablation area percentage, the ablation area percentage can be expressed as ablation volume percentage and ablation area percentage. The calculation of the ablation area and the ablation volume can be obtained by those skilled in the art according to the prior art, and will not be described herein.

The magnetic resonance guidance-based laser ablation evaluation system disclosed in the embodiment shown in the specification can be applied to or implemented by a processor. The processor is an integrated circuit chip having signal processing capabilities. In the implementation process, the steps of the method may be implemented by an integrated logic circuit of hardware in a processor, or certainly, besides a software implementation, the electronic device of the embodiment of the present disclosure does not exclude other implementations, such as a logic device or a combination of software and hardware, and the like, that is, the execution subject of the following processing flow is not limited to each logic unit, and may also be a hardware or a logic device.

In short, the above description is only a preferred embodiment of the present disclosure, and is not intended to limit the scope of the present disclosure. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present specification shall be included in the protection scope of the present specification.

The systems, devices, modules or units illustrated in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. One typical implementation device is a computer. In particular, the computer may be, for example, a personal computer, a laptop computer, a mobile phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.