Eccentric blood flow load shift characterization method, apparatus, and media

Abstract

Provided are a method, device and medium for characterizing eccentric flow load transfer of wall shear stress of a distal native aortic segment after ascending aortic replacement surgery, the method comprising: acquiring postoperative medical image data and a pairable preoperative medical image data of a patient, respectively reconstructing a postoperative aortic model comprising an artificial blood vessel segment and a distal native aortic segment and a preoperative aortic model comprising a native aortic segment; determining a distal native aortic segment of interest and a preoperative abnormal section, acquiring wall shear stress distribution data thereof and calculating a postoperative eccentricity index and a preoperative eccentricity index; based on a reference mean value and a standard deviation of a corresponding anatomical region in a healthy reference database, calculating a postoperative standardized deviation and a preoperative standardized deviation; based on the standardized deviation, generating a postoperative eccentric load and a healthy reference deviation and a key interest section.

Description

Technical Field

[0001] The embodiments of this disclosure relate to the fields of medical image processing and computational fluid dynamics, and more specifically to a method, apparatus, and non-transitory computer-readable storage medium for characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after ascending aortic replacement surgery. Background Technology

[0002] Ascending aortic replacement surgery is a common surgical procedure for treating ascending aortic diseases such as aortic aneurysms and dissections. This surgery usually replaces the diseased ascending aortic segment with an artificial blood vessel, but the aortic arch, distal aortic arch, and proximal descending aorta downstream of the anastomosis of the artificial blood vessel are usually preserved as the patient's original aortic segment.

[0003] However, after ascending aortic replacement surgery, the artificial blood vessel replaces the original dilated ascending aortic segment. The abnormal eccentric wall shear force may no longer be concentrated in the original preoperative dilated ascending aortic region, but instead be reconcentrated in the preserved native aortic segment downstream of the distal anastomosis of the artificial blood vessel. This will lead to the problem that the downstream native aorta continues to be subjected to postoperative blood flow impact. Current technology lacks a direct quantitative assessment method for whether the distal native aortic segment has been subjected to abnormal blood flow impact. Summary of the Invention

[0004] According to one aspect of this disclosure, at least one embodiment provides a method for characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after ascending aortic replacement surgery, comprising: Obtain the patient's postoperative medical imaging data, and, where possible, obtain the patient's preoperative medical imaging data that can be matched with the preoperative data; A postoperative aortic model including the artificial blood vessel segment and the distal native aortic segment is reconstructed based on postoperative medical imaging data. In addition, a preoperative aortic model including the native aortic segment is reconstructed based on preoperative medical imaging data when matching preoperative data is available. In the postoperative aortic model, the distal native aortic section of interest was determined, and in the case of available matching preoperative data, the preoperative aortic section was determined. Obtain wall shear force distribution data of the distal native aorta section of interest after surgery, and, if matching preoperative data is available, obtain wall shear force distribution data of abnormal sections before surgery. Postoperative eccentricity index is calculated based on wall shear force distribution data of the distal native aorta section of concern after surgery, and preoperative eccentricity index is calculated based on wall shear force distribution data of abnormal sections of the preoperative site when matching preoperative data is available. Based on the postoperative eccentricity index and the reference mean and standard deviation of the anatomical region corresponding to the postoperative distal primary aortic focus section in the healthy reference database, the postoperative standardized deviation is obtained. Furthermore, when matching preoperative data is available, the preoperative standardized deviation is obtained based on the preoperative eccentricity index and the reference mean and standard deviation of the anatomical region corresponding to the preoperative abnormal section in the healthy reference database. Based on postoperative standardized deviation and preoperative standardized deviation when matching preoperative data is available, postoperative eccentricity load, health reference deviation, and key focus sections are generated.

[0005] According to another aspect of this disclosure, at least one embodiment provides a device for characterizing the shear force eccentric blood flow load transfer of the distal native aortic segment wall after ascending aortic replacement surgery, comprising: a memory for storing computer instructions; and a processor for reading the computer instructions from the memory and executing a method according to at least one embodiment of this disclosure.

[0006] According to another aspect of this disclosure, at least one embodiment provides a non-transitory computer-readable storage medium having computer instructions stored thereon, wherein, when executed by a processor, the computer instructions cause the processor to perform a method according to at least one embodiment of this disclosure. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 shows a schematic diagram of a system for implementing a method for characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after at least one embodiment of the present disclosure following ascending aortic replacement surgery.

[0009] Figure 2A A flowchart is shown of a method for characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after ascending aortic replacement surgery according to an embodiment of the present disclosure.

[0010] Figure 2B A flowchart is shown for a method of characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after ascending aortic replacement surgery according to another embodiment of the present disclosure.

[0011] Figure 3 A schematic diagram of preoperative-postoperative centerline generation, cross-sectional positioning, and eccentric blood flow load transfer according to at least one embodiment of the present disclosure is shown.

[0012] Figure 4 A schematic diagram of WSSE calculation and preoperative-postoperative eccentric load transfer characterization according to at least one embodiment of the present disclosure is shown.

[0013] Figure 5 A block diagram of an eccentric blood flow load transfer characterization device for distal native aortic segment wall shear force after ascending aortic replacement surgery according to at least one embodiment of the present disclosure is shown. Detailed Implementation

[0014] Referring now to specific embodiments of this disclosure, examples of which are illustrated in the accompanying drawings. Although this application will be described in conjunction with specific embodiments, it will be understood that it is not intended to limit this application to the described embodiments. Rather, it is intended to cover variations, modifications, and equivalents included within the spirit and scope of this disclosure. It should be noted that the method steps described herein can be implemented by any functional block or functional arrangement, and any functional block or functional arrangement can be implemented as a physical entity or a logical entity, or a combination of both.

[0015] In this article, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0016] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0017] To facilitate understanding of the technical solutions disclosed herein, the following provides a unified explanation and definition of key terms, abbreviations, and symbols used in the specification: Wall shear force (WSS) eccentricity index (MD-WSSE) of the preoperative maximum equivalent diameter section: used to quantify the degree of non-uniformity of blood flow shear force distribution on the preoperative maximum equivalent diameter section, where MD represents the maximal diameter section.

[0018] Anterior arch wall shear force eccentricity index (AA-WSSE): used to quantify the degree of non-uniformity of blood flow shear force distribution on the anterior arch section after surgery, where AA represents the anterior arch (or archanterior section), which in this invention refers to the original vessel section from the distal end of the artificial blood vessel to the anterior end of the aortic arch after surgery.

[0019] Postoperative distal native aortic wall shear force eccentricity index (DS-WSSE): used to quantify the degree of unevenness in the distribution of blood flow shear force on the postoperative distal native aortic wall. DS represents the distal segment, which is the aortic segment downstream of the distal anastomosis of the artificial blood vessel that is still composed of the patient's own blood vessels, including the anterior end of the aortic arch, the distal end of the aortic arch, and the proximal end of the descending aorta.

[0020] Load shift: refers to the eccentric WSS load of the preoperatively dilated ascending aortic segment no longer acting on the replaced segment after surgery, but may be concentrated on the original vascular segment at the anterior end of the arch that is preserved after surgery.

[0021] Health reference deviation: refers to the degree of deviation of MD-WSSE or AA-WSSE from the mean and standard deviation of the same cross-section of the health reference population.

[0022] Wall Shear Force Eccentricity Index (WSSE): Used to quantify whether the WSS within a cross section is significantly concentrated on a certain side wall.

[0023] Ascending aortic replacement surgery replaces the dilated or diseased segment of the ascending aorta with an artificial blood vessel. However, the aortic arch, distal aortic arch, and proximal descending aorta downstream of the anastomosis of the artificial blood vessel are usually still the patient's own native aortic segments. In other words, the surgery treats the diseased segment of the ascending aorta, but the downstream native aorta continues to be subjected to postoperative blood flow impact.

[0024] Postoperatively, blood needs to pass through the aortic valve orifice or artificial valve orifice, the proximal anastomosis, the main body of the artificial blood vessel, and the distal anastomosis before entering the distal native aortic segment. The orientation and curvature of the artificial blood vessel, the angle of the distal anastomosis, the transition between the artificial blood vessel and the native aorta, and the direction of jet flow from the valve orifice can all alter the flow direction and the distribution of stress on the blood wall as it enters the downstream native aorta.

[0025] In some postoperative cases, the abnormal blood flow load that was originally acting on the dilated ascending aorta region may decrease after surgery, but it may also be re-concentrated along the blood flow direction to the native aortic segment downstream of the distal anastomosis. This phenomenon does not necessarily manifest as an increase in aortic diameter immediately, but may lead to a more concentrated blood flow load on certain local wall surfaces of the downstream native aorta.

[0026] Traditional postoperative follow-up typically focuses on whether the prosthetic blood vessel is patent, whether the anastomosis is stenotic, whether the valve pressure gradient is increased, and whether the diameter of the distal native aorta has changed. These indicators are valuable for detecting clear structural abnormalities, but there is a lack of direct quantitative assessment methods for the question of whether the distal native aortic segment has been subjected to abnormal eccentric blood flow load.

[0027] Computational fluid dynamics can obtain parameters such as velocity field, pressure field, wall shear force, and streamlines based on patient-specific postoperative models. These results can show the spatial distribution of blood flow in the artificial blood vessel and the distal native aorta. However, if only contour maps or single maximum values ​​are output, it is still difficult to explain whether the wall load in a certain cross section is significantly biased to one side, or to determine whether the postoperative blood flow load has shifted from the abnormal area of ​​the original ascending aorta to the more downstream native aortic segment.

[0028] Current evaluation methods after ascending aortic replacement surgery primarily focus on the patency of the prosthetic vessel, anastomotic stenosis, abnormal valve flow velocity or transvalvular pressure gradient, or changes in aortic diameter. However, there is a lack of specific assessment methods for whether the preserved native aortic segment downstream of the prosthetic vessel is subjected to abnormal eccentric blood flow load. This issue needs to be addressed. Existing follow-up methods largely rely on aortic diameter, growth rate, or morphological changes. While these indicators can reflect structural changes, they typically cannot quantify whether localized blood flow load concentration has already occurred in the distal native aortic segment before diameter changes occur. At least one embodiment of this disclosure addresses this issue by separately calculating the preoperative WSSE and postoperative distal focus WSSE, and combining this with standardized results from a health reference, to characterize whether eccentric blood flow load is re-concentrated in the downstream native aortic segment.

[0029] Furthermore, while existing computational fluid dynamics analyses can output wall shear force contour maps, velocity contour maps, and streamline diagrams, these results are typically graphical representations or single maximum values, lacking a technical process to transform the degree of unevenness in wall load distribution within a cross-section into calculable and comparable parameters. At least one embodiment of this disclosure addresses this problem by proposing a cross-sectional wall shear force eccentricity index (WSSE) to quantify whether the WSS within the same cross-section is significantly concentrated on a particular side wall.

[0030] On the other hand, existing methods typically do not clearly distinguish between the preoperative major abnormal section and the postoperative distal native aortic section of concern. The preoperative major abnormal section represents the abnormal load in the preoperative dilated ascending aorta region, while the postoperative distal section of concern represents the native aorta region that is still preserved downstream of the prosthetic vessel. Their locations and technical significance differ. At least one embodiment of this disclosure addresses this issue by using centerline, section sequence, equivalent diameter, distal anastomosis location, aortic branch location, and artificial markers to determine the preoperative maximum diameter section and postoperative sections of concern such as the aortic arch, distal aorta, or proximal descending aorta. Existing methods lack a standardized comparison process that places the preoperative major abnormal section and the postoperative distal native aortic section of concern within a healthy reference range. Different patients have different flow rates, aortic morphology, valve status, and surgical reconstruction methods; comparing only raw contour maps or single raw values ​​lacks comparability. At least one embodiment of this disclosure addresses this issue by outputting the preoperative major abnormal section, postoperative distal section of concern, WSSE, healthy reference deviation, load transfer characterization results, key sections of concern, and calculation logs through a reporting module.

[0031] Furthermore, existing methods lack a systematic characterization process for "load transfer." Even when the wall shear force distribution before and after surgery can be observed separately, it is usually not further explained whether the postoperative eccentric load has shifted from the original abnormal area of ​​the ascending aorta to the downstream native aortic segment such as the aortic arch, distal aortic arch, or proximal descending aorta. At least one embodiment of this disclosure calculates the wall shear force eccentricity index of the preoperative maximum diameter abnormal section and the postoperative distal native aortic section of interest, respectively, and standardizes it by introducing it into a healthy reference database. This constructs a load transfer coefficient and a comprehensive characterization value, thereby quantifying and intuitively characterizing whether the eccentric blood flow load has shifted from the original ascending aortic lesion area to the downstream aortic arch or descending aortic segment.

[0032] Furthermore, existing methods tend to directly interpret postoperative abnormal blood flow load in the distal native aortic segment as an assessment of aortic dilatation, dissection, or disease progression risk, leading to unclear technical boundaries. At least one embodiment of this disclosure clearly defines the output result as "engineered characterization values ​​of eccentric blood flow load and load transfer," and strictly states in the report that it does not directly output disease diagnostic conclusions such as aortic dilatation, dissection, or disease progression risk, thereby clearly defining the technical boundaries and avoiding directly equating hemodynamic parameters with clinical pathological diagnoses.

[0033] Figure 1 shows a schematic diagram of a system for implementing a method for characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after at least one embodiment of the present disclosure following ascending aortic replacement surgery.

[0034] The system is used to input preoperative and postoperative medical images, ultrasound boundary conditions, and health reference data of patients, generate aortic centerline and continuous cross-sectional sequences, locate major abnormal cross-sections before surgery and postoperative distal native aortic sections of concern, calculate the eccentricity index of cross-sectional wall shear force (WSSE), and output the degree of eccentric blood flow load, load transfer characterization results, and key sections of concern in the distal native aortic segment after surgery through health reference standardization and load transfer characterization parameters.

[0035] Note that in at least one embodiment of this disclosure, the distal native aortic segment refers to the aortic region downstream of the distal anastomosis of the artificial blood vessel, which is still composed of the patient's own blood vessels, including but not limited to the anterior end of the aortic arch, the apex of the aortic arch, the distal end of the arch, and the proximal end of the descending aorta. In specific implementation, one or more sections of interest can be selected according to the image coverage and analysis purpose. If the image only covers the anterior end of the aortic arch, the section at the anterior end of the arch can be used as the postoperative section of interest; if the image covers further, the distal end of the arch or the proximal end of the descending aorta can be analyzed.

[0036] like Figure 1 As shown, the system 100 may include a preoperative and postoperative data input and quality control module 101, an aortic centerline and cross-section generation module 102, a preoperative and postoperative cross-section positioning module 103, a cross-section WSS eccentricity index calculation module 104, a health reference standardization module 105, a load transfer characterization module 106, a distal native aortic focus cross-section output module 107, and a human-computer interaction and reporting module 108.

[0037] For example, the preoperative and postoperative data input and quality control module 101 can import the patient's preoperative medical images (such as CTA, MRI), postoperative medical images, echocardiographic velocity or flow data, transvalvular pressure gradient, blood pressure, heart rate, surgical procedure, and prosthetic blood vessel type. The aortic centerline and cross-section generation module 102 can reconstruct the preoperative aortic model and the postoperative prosthetic blood vessel-aortic continuous pathway model based on the input images. It extracts the vessel centerline along the blood flow path and generates a continuous cross-section sequence. The preoperative and postoperative cross-section positioning module 103 can automatically or assistedly locate the preoperative major abnormal cross-sections (such as the maximum diameter cross-section) and the postoperative distal native aortic sections of interest (such as the cross-section at a fixed distance downstream of the distal anastomosis, the cross-section at the arch branch position, etc.) based on the centerline and cross-section sequence.

[0038] Next, the cross-sectional WSS eccentricity index calculation module 104 can extract wall shear force distribution data of the preoperative and postoperative cross-sections based on computational fluid dynamics (CFD) simulation results, and calculate the wall shear force eccentricity index (WSSE) of the preoperative and postoperative cross-sections. The health reference standardization module 105 can compare the calculated WSSE with a preset health reference database to calculate the standardized deviation of the preoperative and postoperative cross-sections. The load transfer characterization module 106 can calculate the load transfer coefficient (Transfer) based on the standardized deviation and generate the load transfer characterization results.

[0039] In addition, the distal native aorta focus section output module 107 can identify and output key focus sections, such as the section with the highest WSSE or the largest deviation. The human-computer interaction and reporting module 108 provides data import, model verification, result display, report generation, and export functions.

[0040] Figure 2A A flowchart of a method 210 for characterizing eccentric blood flow load transfer of distal native aortic segment wall shear force after ascending aortic replacement surgery according to an embodiment of the present disclosure is shown.

[0041] Method 210 includes the following processing steps: Step 211, acquiring the patient's postoperative medical imaging data, and, if compatible preoperative data is available, the patient's preoperative medical imaging data; Step 212, reconstructing a postoperative aortic model including the artificial vascular segment and the distal native aortic segment based on the postoperative medical imaging data, and, if compatible preoperative data is available, reconstructing a preoperative aortic model including the native aortic segment based on the preoperative medical imaging data; Step 213, determining the distal native aortic section of interest in the postoperative aortic model, and, if compatible preoperative data is available, determining the preoperative abnormal section in the preoperative aortic model; Step 214, acquiring the wall shear force distribution data of the distal native aortic section of interest after surgery, and, if compatible preoperative data is available, acquiring the wall shear force distribution data of the preoperative abnormal section. According to step 215, calculate the postoperative eccentricity index based on the wall shear force distribution data of the distal aortic focus section after surgery, and calculate the preoperative eccentricity index based on the wall shear force distribution data of the preoperative abnormal section if matching preoperative data is available; Step 216, obtain the postoperative standardized deviation based on the postoperative eccentricity index and the reference mean and standard deviation of the anatomical region corresponding to the postoperative distal aortic focus section in the healthy reference database, and obtain the preoperative standardized deviation based on the preoperative eccentricity index and the reference mean and standard deviation of the anatomical region corresponding to the preoperative abnormal section in the healthy reference database if matching preoperative data is available; Step 217, generate the postoperative eccentricity load, healthy reference deviation, and focus section based on the postoperative standardized deviation and the preoperative standardized deviation if matching preoperative data is available.

[0042] Thus, by constructing a complete analysis process that includes preoperative abnormal sections and postoperative distal native aortic sections of interest, a systematic characterization of eccentric blood flow load transfer and the generation of key sections of interest were achieved.

[0043] In some embodiments, step 214 includes: based on computational fluid dynamics simulation, inputting blood flow velocity, flow rate, pressure difference, or pressure boundary conditions, calculating the blood flow field of the preoperative aortic model or the postoperative aortic model respectively; and extracting wall shear force distribution data of the preoperative abnormal section or the postoperative distal native aortic section of interest from the blood flow field of the preoperative aortic model or the postoperative aortic model respectively.

[0044] Thus, based on the blood flow boundary conditions input by computational fluid dynamics simulation, wall shear force distribution data are extracted from the blood flow field, providing an accurate physical field basis for the calculation of the eccentricity index and the characterization of load transfer.

[0045] In some embodiments, step 215 of calculating the preoperative eccentricity index or the postoperative eccentricity index includes: extracting the preoperative high quantile and low quantile values ​​and the postoperative high quantile and low quantile values ​​of the wall shear force distribution data of the preoperative abnormal section or the postoperative distal native aorta section of interest; dividing the difference between the preoperative high quantile and low quantile values ​​by the sum of the preoperative high quantile, low quantile values ​​and the denominator correction term to obtain the preoperative eccentricity index; or dividing the difference between the postoperative high quantile and low quantile values ​​by the sum of the postoperative high quantile, low quantile values ​​and the denominator correction term to obtain the postoperative eccentricity index.

[0046] Thus, by using the ratio of the difference between high quantile values ​​and the sum of low quantile values ​​to calculate the eccentricity index, the degree of eccentricity of the shear force distribution on the inner wall of the cross section is effectively quantified, while avoiding interference from individual abnormal noise points on the results.

[0047] In some embodiments, the high percentile value is the wall shear force distribution value corresponding to the first percentile in the wall shear force distribution data arranged from smallest to largest, and the low percentile value is the wall shear force distribution value corresponding to the second percentile in the wall shear force distribution data arranged from smallest to largest, wherein the first percentile is 95% and the second percentile is 5%.

[0048] Thus, by explicitly using the 95th and 5th percentile values ​​instead of extreme values, the influence of extreme outliers is further eliminated, ensuring the robustness and representativeness of the statistical characteristics of the wall shear force distribution. Of course, other values ​​can be used for the first and second percentiles depending on the circumstances.

[0049] In some embodiments, step 216 of calculating the preoperative standardized deviation or the postoperative standardized deviation includes: subtracting the difference between the preoperative eccentricity index and the reference mean of the anatomical region corresponding to the preoperative abnormal section, and then dividing by the standard deviation of the anatomical region corresponding to the preoperative abnormal section to obtain the preoperative standardized deviation; or subtracting the difference between the postoperative eccentricity index and the reference mean of the anatomical region corresponding to the postoperative distal primary aorta section of concern, and then dividing by the standard deviation of the anatomical region corresponding to the postoperative distal primary aorta section of concern to obtain the postoperative standardized deviation.

[0050] Thus, using the reference mean and standard deviation of the corresponding anatomical region in the health reference database as a benchmark, the preoperative eccentricity index and / or postoperative eccentricity index are standardized to obtain their standardized deviation relative to the corresponding health reference distribution. This allows for comparison of results from different cases and different cross-sections on a uniform scale, provided that the anatomical region and calculation caliber are matched.

[0051] In some embodiments, generating postoperative eccentric load and health reference deviation in step 217 includes: calculating preoperative excess deviation when paired preoperative data is available, wherein the preoperative excess deviation is the larger of the preoperative standardized deviation and zero; calculating postoperative excess deviation, wherein the postoperative excess deviation is the larger of the postoperative standardized deviation and zero; calculating a load transfer coefficient, wherein the load transfer coefficient is positively correlated with the postoperative excess deviation and negatively correlated with the preoperative excess deviation; obtaining the local peak wall shear force of the postoperative distal native aorta section of interest, wherein the local peak wall shear force is the maximum value of the wall shear force among all sampling points on the postoperative distal native aorta section of interest; and performing a weighted calculation based on at least two of the following: postoperative excess deviation, load transfer coefficient, local peak wall shear force, and data uncertainty penalty term to obtain postoperative eccentric load and health reference deviation, wherein the data uncertainty penalty term is calculated based on errors in the calculation process.

[0052] Thus, by calculating the preoperative and postoperative excess deviation and load transfer coefficient, and combining the local peak wall shear force and data uncertainty penalty term, the trend of eccentric blood flow load transfer from the original lesion area to the downstream primary segment was accurately quantified.

[0053] In some embodiments, generating postoperative eccentricity load and health reference deviation in step 217 includes: calculating postoperative excess deviation when paired preoperative data is unavailable, wherein the postoperative excess deviation is the larger of the postoperative standardized deviation and zero; obtaining the local peak wall shear force at the postoperative distal native aorta section of interest, wherein the local peak wall shear force is the maximum value of the wall shear force among all sampling points at the postoperative distal native aorta section of interest; and performing a weighted calculation based on at least two of the postoperative excess deviation, local peak wall shear force, and data uncertainty penalty term to obtain postoperative eccentricity load and health reference deviation, wherein the data uncertainty penalty term is calculated based on the error during the calculation process.

[0054] Thus, in the absence of preoperative data, the generation of characterization results based solely on postoperative data reduces computational resource consumption and waiting time, while still enabling effective assessment of the eccentric load on the distal native aortic segment postoperatively.

[0055] In some embodiments, generating the focus section in step 217 includes: determining the focus section by at least one of the following preset screening strategies: determining the section with the highest postoperative eccentricity index; determining the postoperative standardized deviation or the section with the highest postoperative excess deviation; determining the section with the largest load transfer coefficient or postoperative eccentric load and health reference deviation; determining the section located at a specified anatomical location or in response to operator manual marking, wherein the specified anatomical location includes the anterior end of the aortic arch, the apex of the aortic arch, the distal end of the arch, or the proximal end of the descending aorta.

[0056] In this way, by using a variety of preset strategies (such as the highest index, the highest deviation, or a specified anatomical location), key sections of interest can be automatically selected and output, which makes it easier to locate high-risk areas such as the anterior end of the aorta, the distal end of the aorta, or the proximal end of the descending aorta.

[0057] Figure 2B A flowchart is shown for a method of characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after ascending aortic replacement surgery according to another embodiment of the present disclosure. Figure 2B The method 220 shown in the figure, which characterizes the eccentric blood flow load transfer of the distal native aortic segment wall shear force after ascending aortic replacement surgery, can be used as a characterization method for the eccentric blood flow load transfer of the distal native aortic segment wall. Figure 2A This is an example of method 210 for characterizing eccentric blood flow load transfer of distal native aortic segment wall shear force after ascending aortic replacement surgery. For example, Figure 2B Step 221 is Figure 2A An example of step 211 in the text. Figure 2B Step 222 is Figure 2A Example of step 212 in the example. Figure 2B Step 223 is Figure 2A Example of step 213 in the example. Figure 2B Step 224 is Figure 2A Example of step 214 in the example. Figure 2B Step 225 in the text can correspond to Figure 2A Step 215 in the process. Figure 2B Step 226 is Figure 2A Example of step 216 in the example. Figure 2B Step 227 is Figure 2A Example of step 217 in the example.

[0058] like Figure 2B As shown, preoperative and postoperative data input and quality control can be performed in step 221. In an exemplary and non-limiting example, this step can be implemented by the preoperative and postoperative data input and quality control module 101.

[0059] The preoperative and postoperative data input and quality control module 101 can collect preoperative and postoperative medical imaging data, including the patient's preoperative CTA or MRI images and postoperative CTA or MRI images. The preferred imaging range includes the aortic valve orifice or artificial valve orifice, aortic root, ascending aorta, artificial blood vessel replacement area, proximal anastomosis, artificial blood vessel body, distal anastomosis, aortic arch, distal end of the aortic arch, and proximal descending aorta. Module 101 can also simultaneously collect information such as peak ultrasound velocity, average velocity, transvalvular pressure gradient, blood pressure, heart rate, surgical procedure, valve treatment method, artificial blood vessel diameter, artificial blood vessel length, artificial blood vessel type, and follow-up time points.

[0060] The preoperative and postoperative data input and quality control module 101 can check the integrity of the input data. If the preoperative images cannot show the maximum dilation area of ​​the original ascending aorta, or the postoperative images cannot show the original aortic segment downstream of the distal anastomosis, or if information on velocity, flow, or differential pressure that can be used for CFD calculations is missing, the source of uncertainty can be marked in the report displayed in module 108.

[0061] Module 101 can record the original variables required for subsequent formulas, including velocity, pressure, flow rate, blood density, blood viscosity, centerline coordinates, cross-sectional area, cross-sectional position, distal anastomosis position, wall WSS sampling points, health reference database version, and calculation mode.

[0062] In addition, module 101 can first check whether the preoperative images are sufficient to show the aortic valve orifice, aortic root, aortic sinus, ascending aorta, aortic arch and its main branches; and simultaneously check whether the postoperative images are sufficient to show the aortic valve orifice or prosthetic valve orifice, proximal anastomosis, main body of the prosthetic vessel, distal anastomosis, and the native aortic segment downstream of the distal end of the prosthetic vessel. If the postoperative images can cover the aortic arch, the distal part of the arch or the proximal part of the descending aorta, then module 101 can include these areas in the candidate scope of interest.

[0063] Module 101 can also check whether the ultrasound velocity, flow rate, or differential pressure information is sufficient to support subsequent blood flow calculations, check whether preoperative and postoperative images can be analyzed for the same patient, and check whether the health reference database contains reference ranges for the corresponding cross-section or aortic segment. The health reference database can be stored on a local server, a cloud server, or imported into the device as a separate data file.

[0064] The core responsibility of module 101 is to ensure that the input data is complete, of clear origin, and that the calculation mode is verifiable. If preoperative images are missing, postoperative distal native aorta coverage is insufficient, boundary conditions are missing, or image artifacts are severe, the source of uncertainty can be marked in the report via module 108. During the data input phase, module 108 can display preoperative images, postoperative images, ultrasound boundary conditions, artificial blood vessel information, and the health reference database version, and call module 101 to complete the data integrity check.

[0065] In step 222, preoperative and postoperative three-dimensional models, centerlines, and cross-sectional sequences can be generated. According to an example of this disclosure, this step can be implemented by the aortic centerline and cross-sectional generation module 102.

[0066] The aortic centerline and cross-section generation module 102 can reconstruct the preoperative aortic model and the postoperative artificial blood vessel-aortic continuous pathway model, respectively. The preoperative model includes the aortic valve orifice, aortic root, aortic sinus, ascending aorta, aortic arch, and proximal descending aorta. The postoperative model includes the aortic valve orifice or artificial valve orifice, proximal anastomosis, artificial blood vessel body, distal anastomosis, aortic arch, distal end of the aortic arch, and proximal descending aorta.

[0067] Module 102 can extract the centerline along the preoperative and postoperative aortic pathway and generate multiple cross-sections approximately perpendicular to the centerline. Each cross-section records its center point, cross-sectional area, equivalent diameter, maximum diameter, minimum diameter, anatomical region, and distance from the distal anastomosis.

[0068] The equivalent diameter of the cross section can be calculated using, for example, the following formula: .

[0069] in, A This represents the area of ​​the tube cavity at that cross-section. This represents the equivalent diameter of the cross-section. This formula is used to convert cross-sections of different shapes into cross-sectional dimensions that are easy to compare.

[0070] In this step, the diameter, length, and model of the artificial blood vessel are only used as model dimensions, the range of the artificial blood vessel segment, and report traceability information, and are not used as the basis for judging the abnormality of the artificial blood vessel material itself.

[0071] Module 102 can output preoperative centerline, postoperative centerline, preoperative cross-sectional sequence, postoperative cross-sectional sequence, artificial blood vessel segment marker, distal anastomosis marker, distal native aortic segment marker, and model quality control log.

[0072] In step 223, the preoperative major abnormal sections and the postoperative distal native aortic section of interest can be located. According to an example of this disclosure, this step can be implemented by the preoperative and postoperative section location module 103.

[0073] The preoperative and postoperative section localization module 103 locates the main abnormal sections before surgery and the distal native aorta section of concern after surgery based on the centerline and section sequence generated by module 102.

[0074] The preoperative major abnormal section is preferably the section with the largest preoperative diameter, but it can also be the section with the largest equivalent diameter, the section with the largest lumen area, the section with the most obvious local dilation, or the section of concern marked by the operator based on imaging. If the section with the largest equivalent diameter is used, it can be expressed as, for example, by the following formula:

[0075] in, Indicates the equivalent diameter of each cross-section before surgery. This represents the maximum diameter section before surgery. This section is used to represent the main abnormal load area of ​​the ascending aorta before surgery.

[0076] The postoperative distal native aortic focus section refers to the candidate section downstream of the distal anastomosis of the prosthetic vessel, where the native aorta remains intact. This focus section can be located at the anterior end of the aortic arch, the apex of the aortic arch, the distal end of the aortic arch, the proximal end of the descending aorta, or other distal native aortic regions defined along the centerline. The system can locate the postoperative focus section in the following ways: first, based on a fixed distance downstream of the distal anastomosis; second, based on the location of the aortic arch branches; third, based on locations with significant changes in centerline curvature; fourth, based on the largest WSSE candidate region; and fifth, based on operator markings.

[0077] Taking a fixed distance downstream of the distal anastomosis as an example, the section of interest can be expressed by the following formula:

[0078] in, Indicates the position of the distal anastomosis on the centerline. This indicates the preset downstream distance. This indicates the section of the distal native aorta of interest after surgery. DS stands for distal segment, i.e., the distal native aortic segment.

[0079] In a specific embodiment, if the front end of the arch is selected as the postoperative focus section, this section can be labeled AA. section AA stands for arch anterior or the anterior part of the aortic arch. It should be noted that AA... section Just DS section As one embodiment, the scope of protection of at least one embodiment of this disclosure should not be limited to the front end of the bow.

[0080] Module 103 can output the preoperative major abnormal cross sections, the postoperative distal native aorta section of interest, the cross section location method, cross section coordinates, the region to which the cross section belongs, the distance between the cross section and the distal anastomosis, and the cross section location reliability. Module 103 is only responsible for cross section location; it does not calculate WSS, does not calculate WSSE, and does not output the final load transfer results.

[0081] Figure 3 A schematic diagram of preoperative-postoperative centerline generation, cross-sectional positioning, and eccentric blood flow load transfer according to at least one embodiment of the present disclosure is shown.

[0082] Figure 3The demonstration showed that the aortic model was first reconstructed from preoperative and postoperative images using medical imaging, and the centerline was extracted. Then, the maximum diameter section of the ascending aorta (representing the original lesion area) was located before the operation, and the original aortic section of interest (such as the arch or proximal descending aorta) downstream of the distal anastomosis after the operation was located.

[0083] like Figure 3 As shown, the blood flow in the preoperative model was significantly eccentric, and the postoperative model still exhibited eccentricity.

[0084] return Figure 2B In step 224, hemodynamic calculations and cross-sectional WSS extraction can be performed. In an exemplary and non-limiting example, the above steps can be implemented by the cross-sectional WSS eccentricity index calculation module 104.

[0085] The cross-section WSS eccentricity index calculation module 104 is used to receive the preoperative major abnormal cross-section and the postoperative distal native aortic focus cross-section output by module 103, and calculate the degree of eccentricity of the shear force distribution on the inner wall of each cross-section in combination with CFD or other velocity field calculation results.

[0086] Within a certain cross section, module 104 extracts multiple WSS values ​​along the circumference of the cross section or in the region adjacent to the wall surface as wall shear force distribution data for that cross section, and calculates the high and low quantile values ​​of the WSS distribution within that cross section. To reduce the influence of a single outlier, the 95th percentile and 5th percentile are preferably used, rather than extreme values ​​(maximum and minimum values).

[0087] In step 225, the cross-section WSSE calculation can be performed. The above steps can be implemented by the cross-section WSS eccentricity index calculation module 104.

[0088] At least one embodiment of this disclosure proposes a cross-sectional wall shear force eccentricity index (WSSE) to quantify whether the WSS within the same cross-section is significantly concentrated on a certain side wall. For example, WSSE can be calculated using the following formula:

[0089] Where s represents a certain cross section. This represents the 95th percentile value of the WSS distribution across this cross section. The 5th percentile value of the WSS distribution in this cross section is represented by ε, where ε represents the smallest positive number to prevent the denominator from being zero. The higher the WSSE, the more uneven the WSS distribution in this cross section, and the more obvious the eccentricity.

[0090] In this disclosure, the 95th percentile value refers to the value located at the 95th percentile after sorting all wall shear force (WSS) values ​​at all wall sampling points on the cross-section in ascending order. This value represents the relatively high WSS level achievable by the vast majority (95%) of sampling points within the cross-section, but excludes extremely high values ​​(such as computational noise). Similarly, the 5th percentile value refers to the value located at the 5th percentile after sorting, representing the relatively low WSS level of the vast majority of sampling points within the cross-section, excluding extremely low values.

[0091] For preoperative major abnormal sections, module 104 can calculate the preoperative section WSSE, for example, using the following formula:

[0092] in, This indicates the preoperative major abnormal section. If the preoperative major abnormal section uses the maximum diameter section, this index can also be called MD-WSSE.

[0093] For the postoperative distal native aortic section of concern, module 104 can calculate the postoperative distal section WSSE, for example, using the following formula:

[0094] in, This indicates the postoperative distal native aorta section of interest. If the section of interest is selected as the anterior section of the aorta, this index can be called the anterior aorta WSSE (AA-WSSE); if the section of interest is selected as the distal aorta or the proximal descending aorta, it can be called the WSSE of that section.

[0095] Module 104 can calculate WSSE for one or more postoperative distal sections of interest and generate a WSSE distribution curve along the centerline. This curve can be used to identify sections with prominent eccentric WSS in the postoperative distal native aortic segment.

[0096] Figure 4 A schematic diagram of WSSE calculation and preoperative-postoperative eccentric load transfer characterization according to at least one embodiment of the present disclosure is shown.

[0097] Figure 4 The paper demonstrates the extraction of wall shear force (WSS) distribution data from major abnormal sections preoperatively (such as the maximum diameter of the ascending aorta) and postoperative distal native aortic sections of interest (such as the arch or proximal descending aorta). The WSSE is obtained by calculating the ratio of the difference between high quantile values ​​(such as the 95th percentile) and low quantile values ​​(such as the 5th percentile) to the sum of the values, in order to quantify the degree of eccentricity of the wall load within the section.

[0098] Next, return Figure 2B In step 226, health reference standardization can be performed.

[0099] In an exemplary and non-restrictive example, these steps can be implemented by the health reference standardization module 105.

[0100] The health reference standardization module 105 receives the preoperative cross-sectional WSSE and postoperative distal cross-sectional WSSE output from module 104 and compares them with a health reference database or a low-abnormality reference cohort to obtain the standardized deviation. The function of module 105 is to convert WSSE from different patients, different cross-sections, and different calculation batches to a comparable scale.

[0101] A healthy reference database may contain WSSE reference values ​​for healthy controls or low-abnormality reference cases in different aortic segments. Preferably, the healthy reference database should distinguish between different reference regions, such as the ascending aorta, aortic arch, distal aortic arch, and proximal descending aorta. The reference mean and standard deviation for each reference region should be used as much as possible, avoiding the mixing of different anatomical sites within the same reference range.

[0102] For major abnormal cross sections preoperatively, the standardized deviation can be expressed as, for example, by the following formula:

[0103] in, The wall shear force eccentricity index (WSSE) represents the preoperative major abnormal cross-section. and These represent the mean and standard deviation of WSSE for the region corresponding to the abnormal preoperative cross-section in the health reference database, respectively.

[0104] For the postoperative distal native aortic cross-section of concern, the standardized deviation can be expressed as, for example, by the following formula:

[0105] in, The wall shear force eccentricity index (WSSE) of the distal native aorta at the point of interest after surgery is represented. and The mean and standard deviation of WSSE in the region corresponding to the postoperative distal native aortic focus section are respectively represented in the health reference database.

[0106] If multiple postoperative distal focus sections are analyzed simultaneously, the Z-axis of each section can be calculated separately. post And, for example, the section with the highest degree of deviation can be identified from it using the following formula:

[0107] Among them, Z post,kThis represents the standardized deviation of the k-th postoperative distal focus section (k is a positive integer). This parameter can be used in subsequent module 106 for load transfer characterization.

[0108] Module 105 can also output percentile position and deviation level. For example, if the WSSE of a certain section is higher than the 90th percentile of the healthy reference, it can be marked as high eccentric load; if it is higher than the 95th percentile, it can be marked as significant deviation of eccentric load. The above classification is only used for engineered blood flow load description and is not a conclusion for disease diagnosis.

[0109] In step 227, load transfer characterization and focus section output can be performed.

[0110] In an exemplary and non-limiting example, this step can be implemented by the load transfer characterization module 106 and the distal native aortic focus section output module 107.

[0111] In the step of outputting the load transfer characterization, the load transfer characterization module 106 receives the preoperative WSSE standardized deviation and the postoperative distal native aorta WSSE standardized deviation output by module 105, forming eccentric blood flow load transfer characterization parameters. The core function of this module 106 is to indicate whether the postoperative eccentric blood flow load has been refocused from the original preoperative major abnormal area to the downstream native aortic segment distal to the artificial blood vessel.

[0112] To avoid misunderstandings caused by directly using standardized values ​​that may be negative, this module 106 preferably uses the "partial deviation exceeding the healthy reference range" for calculation. Preoperative and postoperative excess deviations can be defined first, for example, as shown in the following formula:

[0113]

[0114] in, This indicates the deviation of the preoperative major abnormal cross-section from the healthy reference range. This represents the deviation of the distal focus section from the healthy reference range after surgery. If the Z value is less than 0, it means that the section is not higher than the reference mean, and the excess deviation is taken as 0.

[0115] Calculate the load transfer factor, and the load transfer factor is related to the postoperative excess deviation ( It is positively correlated with the preoperative excess deviation ( (Negative correlation)

[0116] In one example, the load transfer factor (Transfer) can be expressed as, for example, by the following formula:

[0117] in, This indicates the excess deviation of the distal focus section after surgery. This represents the excess deviation of the preoperative major abnormal section, and ε represents a very small positive number to prevent the denominator from being zero. The higher the Transfer value, the more prominent the postoperative eccentric load of the distal native aortic segment is relative to the preoperative major abnormal load.

[0118] Of course, other formulas can also be used for the load transfer coefficient, as long as the postoperative excess deviation ( The larger the value, the greater the load transfer coefficient, and the greater the preoperative excess deviation ( The smaller the value, the larger the load transfer coefficient.

[0119] If multiple postoperative distal focus sections are analyzed simultaneously, the transfer coefficient can be calculated using the distal section with the highest degree of deviation, as shown in the following formula:

[0120] in, This indicates the highest excess deviation among multiple remote focus sections.

[0121] Module 106 can also, for example, form a comprehensive load transfer characteristic value, LoadTransferScore, by combining the absolute deviation of the distal section after surgery using the following formula:

[0122] in, This indicates the excess deviation of the distal focus section after surgery; Transfer represents the load transfer coefficient. The normalized local peak value (WSS) for this cross-section is represented by U, which represents the data uncertainty or quality control penalty term. U and Conf (confidence level) can have a complementary and inverse relationship, for example... U =1- Conf or U = f (1- Conf ). to These are weighting coefficients, and their sum is 1 (or can be set according to specific needs). If local peak WSS is not required, it can be omitted. .

[0123] LoadTransferScore is not just a mathematical formula; it incorporates "relative change" (Transfer) and "absolute intensity" (…). E post "Local extrema" WSS peak ) and "data quality" UIt solves the problem of the one-sidedness of a single indicator (for example, looking only at the transfer coefficient will ignore the absolute load size, and looking only at the absolute load will ignore the transfer trend), and greatly improves the accuracy of the data representation.

[0124] The output of module 106 may include Transfer, Transfer_max, LoadTransferScore, postoperative distal deviation from the highest cross section, eccentricity direction, and load transfer explanation text. This module does not directly output disease diagnostic conclusions such as aortic dilatation, dissection, or reoperation risk.

[0125] In step 227, a focus section may also be output. In some embodiments, this step may be implemented by the distal native aorta focus section output module 107.

[0126] The distal native aorta focus section output module 107 is used to receive the load transfer characterization results output by module 106, and combine them with the cross-sectional WSS distribution output by module 104, the standardized deviation output by module 105, and the cross-sectional position information output by module 103 to determine the distal native aorta focus sections that need to be highlighted in the report.

[0127] Key sections to focus on include the following categories: First, the distal native aorta section with the highest WSSE postoperatively; Second, Z-sections. post or E post The highest cross section; third, the cross section with the largest Transfer or LoadTransferScore; fourth, the cross section located at a specified position such as the anterior end of the aortic arch, the distal end of the aortic arch, or the proximal end of the descending aorta; fifth, the cross section manually marked by the operator according to clinical or research purposes.

[0128] Module 107 can output the three-dimensional location, section name, distance from the distal anastomosis, WSSE value, health reference deviation, eccentricity direction, local WSS distribution diagram, and load transfer characterization results of the sections of interest. For example, if the front end section AA of the bow... section WSSE and Z post If all values ​​are significantly higher than the reference range, they can be marked as sections of concern for eccentric loading at the anterior end of the aorta; if the deviation of the proximal descending aorta section is even greater, the proximal descending aorta section can be marked as a section of particular concern.

[0129] Module 107 does not recalculate WSSE, re-perform health reference normalization, or recalculate Transfer. Its function is to transform the aforementioned calculation results into displayable, verifiable, and exportable key section output results.

[0130] In step 228, confidence level calculation and standardized report output can be performed. In an exemplary and non-limiting example, these steps can be implemented by the human-computer interaction and reporting module 108.

[0131] The human-computer interaction and reporting module 108 provides functions such as data import, model display, centerline verification, section verification, WSSE result display, load transfer result display, manual modification record, standardized report generation, and multi-format data export. The human-computer interaction and reporting module 108 can also serve as a unified interaction entry point and result display exit point for modules 101 to 107.

[0132] During the data input phase, module 108 can display preoperative images, postoperative images, ultrasound boundary conditions, artificial blood vessel information, and the health reference database version, and call module 101 to complete data integrity checks. During the model verification phase, module 108 can display the preoperative and postoperative models, centerline, cross-sectional sequences, distal anastomosis location, and distal native aortic segment markers generated by module 102. During the cross-sectional verification phase, module 108 can display the preoperative major abnormal cross-sections and postoperative distal sections of interest located by module 103, and allow the user to manually confirm or adjust them.

[0133] During the results display phase, module 108 can display the cross-sectional WSS distribution, WSSE values, and WSSE curves along the centerline direction calculated by module 104; display the health reference deviation generated by module 105; display the Transfer and LoadTransferScore generated by module 106; and display the key focus cross-sections determined by module 107.

[0134] Module 108 should record all manual modifications, including the modification time, the modified item, the parameters before and after the modification, and the operator information. For example, if the user modifies the centerline, the location of the distal anastomosis, the preoperative major abnormal section, the postoperative distal section of concern, the health reference database version, or the CFD boundary conditions, the system should automatically record and write it to the calculation log.

[0135] The final report should include at least the following: input data completeness, preoperative and postoperative model quality, centerline and cross-sectional localization results, preoperative major abnormal cross-sections, postoperative distal native aorta focus cross-sections, WSSE, healthy reference deviation, Transfer, LoadTransferScore, focus cross-sections, formula version, healthy reference database version, computational quality control results, and manual modification log. The report should clearly state that the system outputs engineered characterization results of eccentric blood flow load and load transfer in the distal native aortic segment, and does not constitute a disease diagnosis or directly provide a treatment plan.

[0136] Optionally, module 108 supports various export formats, including Word reports, PDF reports, CSV parameter tables, STL 3D models, VTK contour files, HDF5 data packages, and structured database records. For batch case analysis, module 108 also supports automatic export of WSSE, Z_post, Transfer, LoadTransferScore, and key focus sections for subsequent research statistics, engineering validation, or multi-center data archiving.

[0137] To ensure the reliability of the results, the human-computer interaction and reporting module 108 can calculate the confidence level of postoperative eccentric load and deviation from the healthy reference:

[0138] in, This represents the segmentation error. Indicates mesh quality error. Indicates boundary condition error. This indicates the cross-sectional positioning error. This indicates an adaptation error to the health reference database. to This indicates the weight of each error. The closer Conf is to 1, the higher the quality of the input data, model, cross-section localization, and reference database fit.

[0139] Segmentation error represents the error in the geometric boundaries of blood vessels segmented in the 3D model. Mesh quality error represents the error in the shape of the mesh cells used for CFD calculations. Boundary condition error represents the error in the physical boundary conditions of the blood vessel inlets / outlets used for CFD calculations. Section positioning error is characterized by the change in WSSE and other results after the section is moved back and forth along the centerline, the plane angle is changed, or the positioning is repeated. Health reference database adaptation error is determined based on the anatomical segment, calculation method, cardiac cycle, resolution, and population matching degree. All error terms can be uniformly normalized to the same direction and range.

[0140] The report clearly states that at least one embodiment of this disclosure outputs the engineered characterization results of eccentric blood flow load and load transfer in the distal native aortic segment, without directly outputting disease diagnosis conclusions such as aortic dilation, dissection, and reoperation risk, nor directly providing treatment plans.

[0141] Through the above method embodiments, this disclosure realizes fully automated processing from image data input to load transfer characterization output, and can accurately quantify the eccentric blood flow load and its transfer trend in the distal native aortic segment after surgery.

[0142] The complete two-timepoint (i.e., preoperative and postoperative) scheme has been described above. In another embodiment, if the patient lacks available preoperative images or the preoperative model quality is insufficient, at least one embodiment of this disclosure can still perform single-timepoint eccentric WSS load characterization of the distal native aortic segment based on postoperative images and postoperative blood flow calculations. This embodiment does not calculate preoperative WSSE or transfer relative to the preoperative major abnormal section, but it can still calculate the postoperative distal section WSSE, healthy reference deviation, and key focus section.

[0143] In this embodiment, for example, when preoperative medical imaging data of the subject cannot be obtained or the quality of the preoperative model does not meet the preset quality threshold, a postoperative single-time-point analysis mode is executed. In the postoperative single-time-point analysis mode: the step of determining the preoperative abnormal section based on the preoperative aortic model is skipped; the steps of calculating the preoperative eccentricity index, preoperative standardized deviation, and preoperative excess deviation are skipped; the step of calculating the load transfer coefficient is skipped; the postoperative eccentricity index is calculated only based on the wall shear force distribution data of the postoperative distal native aorta section of interest; the postoperative standardized deviation is calculated based on the postoperative eccentricity index; the postoperative eccentricity load and healthy reference deviation are generated based on the postoperative standardized deviation, and the characterization results include the identified key sections of interest, which are the sections with the highest postoperative eccentricity index, postoperative standardized deviation, or postoperative excess deviation; wherein, the postoperative eccentricity load and healthy reference deviation do not include the load transfer coefficient.

[0144] For example, in the postoperative single-time-point analysis mode, according to Figure 2B In step 221, postoperative images and boundary conditions can be entered.

[0145] Module 101 inputs postoperative CTA, MRI, 4D Flow MRI, or other imaging data that can be used to reconstruct the postoperative aortic access, and inputs ultrasound velocity, flow rate, transvalvular pressure gradient, blood pressure, heart rate, prosthetic vessel type, and a healthy reference database. Due to the lack of preoperative images, the system marks the case as "postoperative single-time point analysis mode".

[0146] according to Figure 2B Step 222 in the process can generate the postoperative model, centerline and distal native aortic cross-sectional sequence.

[0147] Module 102 reconstructs a continuous pathway model of the artificial blood vessel-aorta after surgery, extracts the centerline, and generates a sectional sequence of the distal native aorta starting downstream of the distal anastomosis of the artificial blood vessel. This sectional sequence covers the anterior end of the aortic arch, the apex of the arch, the distal end of the arch, and the proximal end of the descending aorta.

[0148] according to Figure 2B Step 223 in the procedure allows for the localization of the distal focus section after surgery.

[0149] Module 103 locates one or more postoperative distal native aortic sections of interest based on image coverage and analysis objectives. These sections can be determined by factors such as a fixed distance downstream of the distal anastomosis, the location of the aortic arch branches, locations with significant changes in centerline curvature, operator-marked locations, or automatic screening along the centerline candidate sections.

[0150] according to Figure 2B In steps 224 and 225, the postoperative cross-section WSS and WSSE are calculated.

[0151] Module 104, for example, extracts the WSS distribution at each distal section of interest based on postoperative blood flow calculations using the following formula, and calculates the WSSE:

[0152] Here, s represents a postoperative distal focus section. If the system analyzes multiple sections, a WSSE distribution curve along the centerline direction can be generated.

[0153] according to Figure 2B Step 226 in the calculation can be used to calculate the deviation from the health reference.

[0154] Module 105, for example, compares the WSSE of each postoperative distal focus section with the corresponding regional healthy reference value using the following formula to calculate the standardized deviation:

[0155] in, This represents the WSSE of the k-th postoperative distal focus section. and These represent the health reference mean and standard deviation for that region, respectively.

[0156] Furthermore, the postoperative excess deviation can be calculated using the following formula:

[0157] For example, the distal native aortic section with the highest degree of deviation can be identified using the following formula:

[0158] according to Figure 2B In steps 227 and 228, the single-time point characterization results and reports of the distal native aorta can be output.

[0159] Module 107 outputs the postoperative distal native aortic key focus sections, including the highest WSSE section and Z-section. post highest section or E postThe highest cross-section. Module 108 outputs a single-time-point standardized report, including the postoperative model, centerline, distal focus section, WSS distribution, WSSE, healthy reference deviation, focus section, and calculation log.

[0160] The report can clearly mark "postoperative single-time point analysis mode" and explain that this embodiment cannot calculate the preoperative-postoperative load transfer coefficient Transfer, but can only characterize the eccentric WSS load deviation of the distal native aortic segment relative to the healthy reference range after surgery.

[0161] This embodiment may omit steps related to preoperative data, such as "reconstructing the preoperative aortic model based on preoperative medical imaging data" and "calculating the preoperative eccentricity index," and can be considered as an optional alternative or dependent embodiment.

[0162] This way, only postoperative data needs to be processed, shortening the computation path and significantly reducing computational resource consumption and waiting time.

[0163] In summary, at least one embodiment of this disclosure proposes a method for characterizing eccentric blood flow load in the distal native aorta after ascending aortic replacement surgery. This method not only focuses on whether the artificial blood vessel is patent or whether the anastomosis is stenotic, but also includes the aortic arch, the distal end of the aortic arch, and the proximal end of the descending aorta, which are still composed of the patient's own blood vessels downstream of the distal anastomosis of the artificial blood vessel, in the postoperative blood flow load analysis.

[0164] At least one embodiment of this disclosure proposes a cross-sectional wall shear force eccentricity index (WSSE) for characterizing eccentric blood flow load in the distal native aorta after ascending aortic replacement surgery. This index is used to quantify whether the WSS within the same cross-section is significantly concentrated on a certain side wall, transforming the eccentric distribution, which could only be observed through WSS contour maps, into a calculable, comparable, and traceable cross-sectional quantitative parameter.

[0165] The present disclosure establishes a corresponding analysis process for the distal native aortic eccentric blood flow load characterization method after ascending aortic replacement surgery, based on at least one embodiment. The system can locate the preoperative maximum diameter section or other major abnormal sections, and simultaneously locate the distal sections of interest such as the anterior end of the aortic arch, the distal end of the aortic arch, or the proximal end of the descending aorta, and calculate their respective WSSEs.

[0166] At least one embodiment of this disclosure provides a method for characterizing eccentric blood flow load in the distal native aorta after ascending aortic replacement surgery. This method compares the degree of eccentric load between different cross-sections using healthy reference standardization and excess deviation. The system places the preoperative cross-section WSSE and the postoperative distal cross-section WSSE into the healthy reference range of the corresponding region to obtain Zo. pre Z post E preand E post Standardized results improve comparability between different patients, different cross-sections, and different batches.

[0167] Furthermore, in at least one embodiment of the present disclosure, a method for characterizing eccentric blood flow load in the distal native aorta after ascending aortic replacement surgery is established to characterize whether the postoperative eccentric WSS load has been re-concentrated from the main abnormal area of ​​the original ascending aorta to the native aortic segment downstream of the artificial blood vessel through parameters such as Transfer, Transfer_max and LoadTransferScore, and outputs the key focus section.

[0168] The method for characterizing distal native aortic eccentric blood flow load after ascending aortic replacement surgery according to at least one embodiment of this disclosure can supplement the shortcomings of existing postoperative evaluations that only focus on the prosthetic vessel and anastomosis. By including the distal native aortic segment in the analysis, the system can characterize whether the preserved vessel downstream of the prosthetic vessel is subjected to eccentric WSS load.

[0169] Furthermore, in the method for characterizing distal native aortic eccentric blood flow load after ascending aortic replacement surgery according to at least one embodiment of this disclosure, WSS contour maps can be converted into cross-sectional quantization results. With WSSE, users no longer rely solely on color contour maps to determine whether the load is biased to one side, but can obtain clear cross-sectional eccentricity parameters.

[0170] At least one embodiment of this disclosure supports a comparison of preoperative and postoperative load location changes. The system can compare the eccentric load status of the preoperative major abnormal section and the postoperative distal section of interest, thereby characterizing whether the postoperative blood flow load is refocused on the downstream native aortic segment.

[0171] At least one embodiment of this disclosure can improve comparability between cases and between cross-sections. Through health reference standardization and excess deviation, WSSE results from different patients, different aortic regions, and different calculation batches can be interpreted on a uniform scale.

[0172] The distal native aortic eccentric blood flow load characterization method of at least one embodiment of the present disclosure can output a section of focus and can identify distal native aortic sections with high WSSE, high healthy reference deviation, or high load transfer characterization values, such as the anterior end of the aorta, the distal end of the aorta, or the proximal end of the descending aorta, which facilitates subsequent review and reporting.

[0173] Furthermore, in the method for characterizing distal native aortic eccentric blood flow load after ascending aortic replacement surgery according to at least one embodiment of this disclosure, a traceable standardized report can be generated. The report can record the preoperative major abnormal cross section, postoperative distal focus cross section, WSSE, healthy reference deviation, Transfer, LoadTransferScore, focus cross section, calculation mode, reference database version, and manual modification log, which facilitates review, archiving, and batch comparison.

[0174] Figure 5 A block diagram of an eccentric blood flow load transfer characterization device for distal native aortic segment wall shear force after ascending aortic replacement surgery according to at least one embodiment of the present disclosure is shown.

[0175] The device for characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after ascending aortic replacement may include a processor 510 and a memory 520, the memory 520 being coupled to the processor 510 and storing computer instructions therein for performing the steps of various methods of at least one embodiment of the present disclosure when executed by the processor 510.

[0176] The processor 510 may include, but is not limited to, one or more processors or microprocessors.

[0177] The memory 520 may include, but is not limited to, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (such as hard disks, floppy disks, solid-state drives, removable disks, CD-ROMs, DVD-ROMs, Blu-ray discs, etc.).

[0178] In addition, the electronic device may also include (but is not limited to) a data bus 530, an input / output (I / O) bus 540, a display 550, and input / output devices 560 (e.g., a keyboard, mouse, speaker, etc.).

[0179] The processor 510 can communicate with external displays 550 and input / output devices 560 via the I / O bus 540.

[0180] In one embodiment, the at least one computer instruction may also be compiled into or comprise a computer program product or software product, wherein one or more computer instructions, when executed by a processor, perform the steps of the various functions and / or methods in the embodiments described herein.

[0181] A schematic diagram of a non-transitory computer-readable storage medium according to at least one embodiment of the present disclosure is also provided.

[0182] Instructions, such as computer instructions, are stored on a non-transitory computer-readable storage medium. When the computer instructions are executed by a processor, the various methods described above can be performed. Non-transitory computer-readable storage media include, but are not limited to, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (e.g., hard disks, floppy disks, solid-state drives, removable disks, CD-ROMs, DVD-ROMs, Blu-ray discs, etc.). For example, a non-transitory computer-readable storage medium can be connected to a computing device such as a computer, and then, when the computing device executes the computer instructions stored on the computer-readable storage medium, the various methods described above can be performed.

[0183] This disclosure may also include a computer program product capable of performing the methods, steps, and operations given herein. For example, such a computer program product may be a computer software package, computer code instructions, or a computer-readable tangible medium having computer instructions tangibly stored (and / or encoded) thereon, which can be executed by a processor to perform the operations described herein. The computer program product may include packaging materials.

[0184] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The term “such as / for example” as used herein refers to the phrase “such as / for example but not limited to,” and is used interchangeably with it.

[0185] The flowcharts and method descriptions in this disclosure are merely illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the given order. As those skilled in the art will recognize, the steps in the above embodiments can be performed in any order. Words such as "then," "next," etc., are not intended to limit the order of the steps; these words are only used to guide the reader through the description of these methods. Furthermore, any reference to a singular element, such as the use of the articles "a," "one," or "the," is not to be construed as limiting that element to the singular.

[0186] Furthermore, the steps and apparatus in the various embodiments herein are not limited to any one embodiment. In fact, new embodiments can be conceived by combining relevant steps and apparatus in the various embodiments herein based on the concepts of this disclosure, and these new embodiments are also included within the scope of this disclosure.

[0187] The above methods can be implemented in hardware, software, firmware, or any combination thereof.

[0188] Furthermore, modules and / or other suitable means for carrying out the methods and techniques described herein can be downloaded from a server wirelessly when appropriate. Alternatively, the various methods described herein can be provided via a storage component so that the various methods are available when coupled to the storage component. Additionally, any other suitable techniques for providing the methods and techniques described herein to the device can be utilized.

[0189] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit at least one embodiment of the present disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for characterizing the eccentric blood flow load transfer of the distal native aortic segment wall shear force after ascending aortic replacement surgery, characterized in that, include: Obtain the patient's postoperative medical imaging data, and, where possible, obtain the patient's preoperative medical imaging data that can be matched with the preoperative data; A postoperative aortic model including the artificial blood vessel segment and the distal native aortic segment is reconstructed based on the postoperative medical imaging data. In the case that the matching preoperative data can be obtained, a preoperative aortic model including the native aortic segment is reconstructed based on the preoperative medical imaging data. In the postoperative aortic model, the distal native aortic section of interest is determined, and if the matching preoperative data is available, the preoperative abnormal section is determined in the preoperative aortic model. Obtain the wall shear force distribution data of the distal native aorta section of interest after surgery, and, if the matching preoperative data is available, obtain the wall shear force distribution data of the abnormal preoperative section. The postoperative eccentricity index is calculated based on the wall shear force distribution data of the distal native aorta section of concern after surgery, and the preoperative eccentricity index is calculated based on the wall shear force distribution data of the preoperative abnormal section when the matching preoperative data can be obtained. Based on the postoperative eccentricity index and the reference mean and standard deviation of the anatomical region corresponding to the postoperative distal primary aortic focus section in the health reference database, the postoperative standardized deviation is obtained. Furthermore, if the matching preoperative data can be obtained, the preoperative standardized deviation is obtained based on the preoperative eccentricity index and the reference mean and standard deviation of the anatomical region corresponding to the preoperative abnormal section in the health reference database. Based on the postoperative standardized deviation and the preoperative standardized deviation when the paired preoperative data is available, postoperative eccentricity load, health reference deviation, and key focus sections are generated.

2. The method according to claim 1, characterized in that, Calculating the preoperative eccentricity index or the postoperative eccentricity index includes: Extract the wall shear force distribution data of the preoperative abnormal section or the postoperative distal native aorta section of interest, specifically the preoperative high quantile and low quantile values, and the postoperative high quantile and low quantile values. The preoperative eccentricity index is obtained by dividing the difference between the preoperative high quantile and the preoperative low quantile by the sum of the preoperative high quantile, the preoperative low quantile, and the denominator correction term; or The postoperative eccentricity index is obtained by dividing the difference between the postoperative high quantile and the postoperative low quantile by the sum of the postoperative high quantile, the low quantile, and the denominator correction term.

3. The method according to claim 2, characterized in that, The high percentile value is the wall shear force distribution value corresponding to the first percentile in the wall shear force distribution data arranged from smallest to largest, and the low percentile value is the wall shear force distribution value corresponding to the second percentile in the wall shear force distribution data arranged from smallest to largest, wherein the first percentile is 95% and the second percentile is 5%.

4. The method according to claim 1, characterized in that, Calculating the preoperative standardized deviation or the postoperative standardized deviation includes: The preoperative standardized deviation is obtained by subtracting the reference mean of the anatomical region corresponding to the preoperative abnormal cross-section from the preoperative eccentricity index, and then dividing by the standard deviation of the anatomical region corresponding to the preoperative abnormal cross-section; or The postoperative standardized deviation is obtained by subtracting the difference between the postoperative eccentricity index and the reference mean of the anatomical region corresponding to the postoperative distal primary aortic focus section, and then dividing by the standard deviation of the anatomical region corresponding to the postoperative distal primary aortic focus section.

5. The method according to claim 1, characterized in that, The generated postoperative eccentric load and healthy reference deviation include: If the matching preoperative data is available, calculate the preoperative excess deviation, which is the larger of the preoperative standardized deviation and zero. Calculate the postoperative excess deviation, which is the larger of the postoperative standardized deviation and zero. Calculate the load transfer coefficient, which is positively correlated with the postoperative excess deviation and negatively correlated with the preoperative excess deviation; The local peak wall shear force of the distal native aorta at the postoperative focus section is obtained, and the local peak wall shear force is the maximum value of the wall shear force among all sampling points on the postoperative distal native aorta at the focus section; The postoperative eccentric load and healthy reference deviation are obtained by weighted calculation based on at least two of the following: the postoperative excess deviation, the load transfer coefficient, the local peak wall shear force, and the data uncertainty penalty term. The data uncertainty penalty term is calculated based on the error in the calculation process.

6. The method according to claim 1, characterized in that, The generated postoperative eccentric load and healthy reference deviation include: In the absence of the available preoperative matching data, the postoperative excess deviation is calculated, which is the larger of the postoperative standardized deviation and zero. The local peak wall shear force of the distal native aorta at the postoperative focus section is obtained, and the local peak wall shear force is the maximum value of the wall shear force among all sampling points on the postoperative distal native aorta at the focus section; The postoperative eccentric load and healthy reference deviation are obtained by weighted calculation based on at least two of the following: the postoperative excess deviation, the local peak wall shear force, and the data uncertainty penalty term. The data uncertainty penalty term is calculated based on the error in the calculation process.

7. The method according to claim 5 or 6, characterized in that, Generate key sections of interest, including: The key focus sections are determined using at least one of the following preset filtering strategies: Determine the section with the highest postoperative eccentricity index; Determine the postoperative standardized deviation or determine the cross section with the highest postoperative excess deviation; Determine the load transfer coefficient or the section with the largest deviation from the postoperative eccentric load and healthy reference. Determine a section located at a specified anatomical location or in response to manual marking by the operator, wherein the specified anatomical location includes the anterior end of the aortic arch, the apex of the aortic arch, the distal end of the arch, or the proximal end of the descending aorta.

8. The method according to claim 1, characterized in that, The acquisition of wall shear force distribution data of the distal native aorta section of interest after surgery, and, if the matching preoperative data is available, acquisition of wall shear force distribution data of the preoperative abnormal section, includes: Based on computational fluid dynamics simulation, blood flow velocity, flow rate, pressure difference, or pressure boundary conditions are input to calculate the blood flow field of the preoperative aortic model or the postoperative aortic model, respectively. Wall shear force distribution data of the abnormal section before surgery or the distal native aortic section of interest after surgery are extracted from the blood flow field of the preoperative aortic model or the blood flow field of the postoperative aortic model.

9. A device for characterizing the shear force eccentric blood flow load transfer of the distal native aortic segment wall after ascending aortic replacement surgery, characterized in that, include: processor; Memory, used to store computer programs; When the processor executes the computer program, it implements the method as described in any one of claims 1-8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-8.

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