A method and system for quantitative analysis of aortic dissection chiral morphology

Abstract

The present application relates to a kind of method and system for quantitatively analyzing aortic dissection chiral topography, belong to image processing technical field.Method includes: obtaining the image of enhanced CT angiography of aortic dissection patient in lying state;Based on the image of enhanced CT angiography, distinguish the true lumen and false lumen of aortic dissection;The chiral topography of the dissection image is measured, and measurement result is obtained;Based on the measurement result, the chiral topography of aortic dissection is quantitatively analyzed.The method is simple to operate, and operability is strong, it is convenient for clinician or technical personnel to understand and master, can relatively accurately describe the change characteristics of dissection spiral morphology.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of image processing, and particularly relates to a method and system for quantitatively analyzing the chiral morphology of aortic dissection. BACKGROUND

[0002] Aortic dissection refers to the intimal tear of the aorta, which changes from a normal single lumen to a true and false lumen. The false lumen can expand into a tumor. The two lumens formed by the tear are called the true lumen and the false lumen. The true lumen is the original unteared lumen, which is the main conduit for supplying oxygenated blood to the distal vasculature, while the false lumen is the new lumen after the tear. Researchers believe that the morphology and expansion of the dissection may be related to various factors such as hemodynamics, vessel wall characteristics, thrombus and intramural hematoma. Intramural hematoma refers to a part of the dissection without obvious intimal tear. Studies have shown that blood flow dynamics plays an important role in the formation and expansion of the dissection. For example, the intimal tear location is related to the maximum local wall shear stress at the distal end of the left subclavian artery, the spiral false lumen morphology is related to spiral blood flow, and blood pressure can affect the development speed of the false lumen. In addition to hemodynamic-related factors, a large number of studies have shown that the microstructure of the vessel wall has a high correlation with the dissection and the expansion of the dissection.

[0003] Since 1990, research on blood flow rotation chirality (an asymmetry that a structure and its mirror image cannot overlap, i.e., chirality) and its potential causes has been reported. However, due to the great individual differences in the geometric morphology of aortic dissection, which can be influenced by various factors such as anatomy, physiology and pathology, there have been few studies on the chiral morphology of aortic dissection. There is no report in China. In foreign literature reports, Johan Bondesson et al. proposed a measurement of the true lumen spiral angle based on the Lagrangian coordinate system, and Anna M. Sailer et al. reconstructed the curved aorta in the human body into a straight line and measured the circumferential size of the true lumen and the false lumen. Both researchers are from Professor Christopher P. Cheng's team of the Department of Vascular Surgery, Stanford University, USA, who tried to quantify the spiral morphology of aortic dissection based on the computed tomography (CT) imaging features of aortic dissection patients. However, both of the above methods are based on three-dimensional measurements, and different parameters of aortic dissection are measured. This three-dimensional image reconstruction measurement method of the aorta is very complex, time-consuming, and difficult to understand. Clinicians cannot easily understand and accept it. Moreover, there is no measurement software based on the above two methods in the existing image post-processing workstations in China, resulting in insufficient understanding of clinicians on the morphological indicators.

[0004] Therefore, there is an urgent need in the clinic for a method that is simple, easy to operate, and can accurately describe the chiral morphology of aortic dissection. SUMMARY

[0005] The main purpose of the present application is to overcome the shortcomings and deficiencies of the prior art, provide a method and system for quantitatively analyzing the chirality of aortic dissection, which is simple to operate, strong in operability, easy for clinicians or technical personnel to understand and master, and can relatively accurately describe the change characteristics of the spiral shape of the dissection.

[0006] According to one aspect of the present application, the present application provides a method for quantitatively analyzing the chirality of aortic dissection, the method comprising the following steps:

[0007] S1: obtaining an enhanced CT angiography image of a patient with aortic dissection in a lying state;

[0008] S2: distinguishing the true lumen and the false lumen of the aortic dissection based on the enhanced CT angiography image;

[0009] S3: measuring the chirality of the dissection image to obtain a measurement result;

[0010] S4: quantitatively analyzing the chirality of the aortic dissection based on the measurement result.

[0011] Preferably, the measurement of the chirality of the dissection image comprises:

[0012] The entire aorta in each CT section is approximated and simplified as an ellipse, and the center point, x-axis and y-axis of the ellipse are determined; wherein the x-axis represents a right ray in the horizontal plane perpendicular to the spine axis direction, which is also the main direction of the entire CT section, and the y-axis is an outward ray of the line on which the true lumen symmetry axis is located, which coincides with the line on which the major axis of the ellipse is located, and the direction of the y-axis changes with the case and the section.

[0013] Preferably, the measurement result comprises a quantitative index of the true lumen chirality, and the quantitative index of the true lumen chirality comprises a true lumen spiral angle, and the true lumen spiral angle is the included angle between the x-axis and the y-axis.

[0014] Preferably, the measurement result comprises a geometric quantitative index related to the chirality of the aortic dissection in the selected region, and the geometric quantitative index comprises a maximum diameter of the blood vessel, a true lumen diameter in the direction of the maximum diameter of the blood vessel, a false lumen diameter in the direction of the maximum diameter of the blood vessel, an intimal sheet length, a true lumen peripheral length, a false lumen peripheral length, a true lumen area and a false lumen area.

[0015] Preferably, the method further comprises:

[0016] The aorta structure is partitioned into six regions, C0, C1, C2, C3, C4 and C5, and the CT image cross-sectional position of the lower end point of each region is recorded, and the cross-sectional level of the CT image is defined as N0, N1, N2, N3, N4 and N5; the maximum diameter of the blood vessel is measured, and the x-axis is taken as the positive direction, and the x-axis is rotated counterclockwise to coincide with the y-axis, and the angle of rotation is the true lumen spiral angle α; according to the positions N0, N1, N2, N3, N4 and N5 of the six CT image cross sections and the true lumen spiral angles α0, α1, α2, α3, α4 and α5, the true lumen spiral angle twist rate in the five regions is calculated, and the calculation formula is:

[0017] The twist rate of the C1 region is (α1-α0) / (N1-N0)

[0018] The twist rate of the C2 region is (α2-α1) / (N2-N1)

[0019] The twist rate of the C3 region is (α3-α2) / (N3-N2)

[0020] The twist rate of the C4 region is (α4-α3) / (N4-N3)

[0021] The twist rate of the C5 region is (α5-α4) / (N5-N4)

[0022] According to the true lumen spiral angle twist rate of the five regions, the chirality shape of the aortic dissection and the chirality size are determined.

[0023] According to another aspect of the present application, the present application also provides a system for quantitatively analyzing the chirality shape of the aortic dissection, which comprises:

[0024] An acquisition module for acquiring the enhanced CT angiography image of the patient in a lying state;

[0025] A division module for distinguishing the true lumen and the false lumen of the aortic dissection based on the enhanced CT angiography image;

[0026] A measurement module for measuring the chirality shape of the dissection image to obtain a measurement result;

[0027] An analysis module for quantitatively analyzing the chirality shape of the aortic dissection based on the measurement result.

[0028] Preferably, the measurement module measures the chirality shape of the dissection image, which comprises:

[0029] The main aorta in each CT section is approximated and simplified as an ellipse, and the center point, x-axis and y-axis of the ellipse are determined; wherein the x-axis represents a right ray in the horizontal plane perpendicular to the direction of the spine axis, which is also the main direction of the entire CT section, and the y-axis is an outward ray of the line on which the true lumen symmetry axis is located, which coincides with the line on which the long axis of the ellipse is located, and the direction of the y-axis changes with the case and the section.

[0030] Preferably, the measurement result includes a quantitative index of the true lumen chiral morphology, and the quantitative index of the true lumen chiral morphology includes a true lumen spiral angle, which is an included angle between the x-axis and the y-axis.

[0031] Preferably, the measurement result includes a geometric quantitative index related to the selected region aortic dissection chiral morphology, and the geometric quantitative index includes a maximum vessel diameter, a true lumen diameter in the direction of the maximum vessel diameter, a false lumen diameter in the direction of the maximum vessel diameter, an intimal flap length, a true lumen peripheral length, a false lumen peripheral length, a true lumen area and a false lumen area.

[0032] Preferably, the dividing module is further used for:

[0033] The aortic structure is partitioned into six regions of C0, C1, C2, C3, C4 and C5, and the CT image cross-sectional positions of the lower end points of each region are recorded, and the cross-sectional layers of the CT image are defined as N0, N1, N2, N3, N4 and N5; the maximum vessel diameter is measured, and the x-axis is taken as the positive direction, and the x-axis is rotated counterclockwise to coincide with the y-axis, and the angle of rotation is the true lumen spiral angle α; according to the positions N0, N1, N2, N3, N4 and N5 of the six CT image cross sections and the true lumen spiral angles α0, α1, α2, α3, α4 and α5, the true lumen spiral angle twist rates in the five regions are calculated, and the calculation formula is:

[0034] The twist rate of the C1 region is (α1-α0) / (N1-N0)

[0035] The twist rate of the C2 region is (α2-α1) / (N2-N1)

[0036] The twist rate of the C3 region is (α3-α2) / (N3-N2)

[0037] The twist rate of the C4 region is (α4-α3) / (N4-N3)

[0038] The twist rate of the C5 region is (α5-α4) / (N5-N4)

[0039] According to the true lumen spiral angle twist rates of the five regions, the chiral morphology and the chiral size of the aortic dissection are determined.

[0040] Beneficial effects: This invention describes and measures the chiral morphological characteristics of aortic dissection in cross-section of CT images in a two-dimensional scale under a natural coordinate system, based on the computed tomography (CT) image features of patients with aortic dissection. The method is simple to operate, highly operable, and easy for clinicians or technicians to understand and master. It can relatively accurately describe the changing characteristics of the spiral morphology of the dissection.

[0041] The features and advantages of the present invention will become clear from the following accompanying drawings and a detailed description of specific embodiments thereof. Attached Figure Description

[0042] Figure 1 This is a flowchart of a method for quantitative analysis of the chiral morphology of aortic dissection;

[0043] Figure 2 This is a schematic diagram of the chiral morphological features of aortic dissection at a two-dimensional scale.

[0044] Figure 3 yes Figure 2 Enlarged schematic diagram of the area at point M in the middle;

[0045] Figure 4 This is a schematic diagram illustrating the chiral morphological characteristics of aortic dissection when the intimal flap presents an arc shape.

[0046] Figure 5 yes Figure 4 Enlarged schematic diagram of the area at point N;

[0047] Figure 6 This is a schematic diagram of the chiral regions of aortic dissection;

[0048] Figure 7 This is a schematic diagram of the system structure for quantitative analysis of the chiral morphology of aortic dissection. Detailed Implementation

[0049] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Example 1

[0051] Figure 1 This is a flowchart illustrating a method for quantitative analysis of the chiral morphology of aortic dissection. (Example) Figure 1 As shown, the present invention provides a method for quantitative analysis of the chiral morphology of aortic dissection, the method comprising the following steps:

[0052] S1: Obtain the enhanced CT angiography image of the patient with aortic dissection in a lying state.

[0053] Specifically, the embodiment is based on the CT angiography (CTA) image of the patient with aortic dissection. When the CTA image of the patient is scanned, the patient is lying on the examination bed in the CT room. The CT cross-sectional image obtained in this way is perpendicular to the direction of the vessel cross section and the spine in some regions of the aorta. Then the aortic parameters obtained by two-dimensional scale measurement at these positions are close to the true parameters.

[0054] S2: Based on the enhanced CT angiography image, distinguish the true lumen and the false lumen of the aortic dissection.

[0055] Specifically, first, the enhanced CT angiography image of the patient with aortic dissection in a lying state is obtained. In the tomographic image with aortic dissection, as shown in Figure 2 , the enhanced true lumen and false lumen of the aortic dissection are distinguished.

[0056] S3: Measure the chiral morphology of the dissection image to obtain a measurement result.

[0057] Preferably, the measurement of the chiral morphology of the dissection image comprises:

[0058] The aorta in each CT cross section is approximated and simplified as an ellipse, and the center point, x-axis and y-axis of the ellipse are determined; wherein the x-axis represents a right ray perpendicular to the spine axis direction in the horizontal plane, which is also the main direction of the entire CT cross section, and the y-axis is an outward ray of the line on which the true lumen symmetry axis is located, which coincides with the line on which the major axis of the ellipse is located, and the direction of the y-axis changes with the case and the cross section.

[0059] Preferably, the measurement result comprises a quantitative index of the true lumen chiral morphology, and the quantitative index of the true lumen chiral morphology comprises a true lumen spiral angle, and the true lumen spiral angle is the included angle between the x-axis and the y-axis.

[0060] Preferably, the measurement result comprises a geometric quantitative index related to the chiral morphology of the aortic dissection in the selected region, and the geometric quantitative index comprises a maximum vessel diameter, a true lumen diameter in the direction of the maximum vessel diameter, a false lumen diameter in the direction of the maximum vessel diameter, an intimal flap length, a true lumen outer peripheral length, a false lumen outer peripheral length, a true lumen area and a false lumen area.

[0061] Specifically, the measurement method is as follows: the aorta in each cross section is approximated and simplified as an ellipse, as shown in Figure 3As shown, the marked part is the overall aortic shape, and AB in the figure is the long axis of the ellipse, CD is the short axis of the ellipse, O is the center of the ellipse; EF is the intimal flap, G is the intersection of the long axis of the ellipse and the intimal flap; the area AEGFA represents the true lumen, and the area CBEGFDC represents the false lumen; the x-axis represents the right ray in the horizontal plane perpendicular to the direction of the spinal axis, which is also the main direction of the entire CT section, and the y-axis is the outward ray of the straight line where the true lumen symmetry axis is located, which coincides with the straight line where the long axis of the ellipse is located. Since the position and direction of the true lumen relative to the blood vessel are different in different sections, the direction of the y-axis changes with the case and the section. Therefore, the angle a between the x-axis and the y-axis is the true lumen spiral angle, AC is the maximum diameter of the blood vessel, GA is the true lumen diameter in the direction of the maximum diameter of the blood vessel, GC is the false lumen diameter in the direction of the maximum diameter of the blood vessel, EF is the length of the intimal flap, arc EAF is the length of the outer periphery of the true lumen, arc EBCDF is the length of the outer periphery of the false lumen, the area of the area AEGFA is the area of the true lumen, and the area of the area CBEGFDC is the area of the false lumen.

[0062] In some cases of aortic dissection, due to the uneven pressure in the true lumen and the false lumen, the aortic dissection intimal flap will swing with the heartbeat. When CT scanning, the intimal flap will be biased towards the true lumen or the false lumen. Therefore, when measuring, the intimal flap shows an arc shape, as shown in Figure 4 and Figure 5 At this time, the angle a between the x-axis and the y-axis is the true lumen spiral angle, AC is the maximum diameter of the blood vessel, GA is the true lumen diameter in the direction of the maximum diameter of the blood vessel, GC is the false lumen diameter in the direction of the maximum diameter of the blood vessel, arc EGF is the length of the intimal flap, arc EAF is the length of the outer periphery of the true lumen, arc ECF is the length of the outer periphery of the false lumen, and the area of the area AEGFA is the area of the true lumen. The area of the area CEGFC is the area of the false lumen.

[0063] The true lumen spiral angle a measured in this way is a quantitative indicator of the chiral morphology of the true lumen. The remaining indicators measured, including the maximum diameter of the blood vessel, the true lumen diameter in the direction of the maximum diameter of the blood vessel, the false lumen diameter in the direction of the maximum diameter of the blood vessel, the length of the intimal flap, the length of the outer periphery of the true lumen, the length of the outer periphery of the false lumen, the area of the true lumen, and the area of the false lumen, are all geometric quantitative indicators related to the chiral morphology of the aortic dissection in the selected region.

[0064] Preferably, the method further comprises:

[0065] The aorta structure is partitioned into six regions, C0, C1, C2, C3, C4 and C5, and the CT image cross-sectional position of the lower end point of each region is recorded, and the cross-sectional level of the CT image is defined as N0, N1, N2, N3, N4 and N5; the maximum diameter of the blood vessel is measured, and the x-axis is taken as the positive direction, and the x-axis is rotated counterclockwise to coincide with the y-axis, and the angle of rotation is the true lumen spiral angle α; according to the positions N0, N1, N2, N3, N4 and N5 of the six CT image cross sections and the true lumen spiral angles α0, α1, α2, α3, α4 and α5, the true lumen spiral angle twist rates in the five regions are calculated, and the calculation formula is:

[0066] The twist rate of the C1 region is (α1-α0) / (N1-N0)

[0067] The twist rate of the C2 region is (α2-α1) / (N2-N1)

[0068] The twist rate of the C3 region is (α3-α2) / (N3-N2)

[0069] The twist rate of the C4 region is (α4-α3) / (N4-N3)

[0070] The twist rate of the C5 region is (α5-α4) / (N5-N4)

[0071] According to the true lumen spiral angle twist rates of the five regions, the chirality shape and the chirality size of the aortic dissection are determined.

[0072] Specifically, as shown in Figure 6 , the horizontal plane of the distal end of the left subclavian artery opening on the aortic arch to the horizontal plane of the small bending side vertex of the aortic arch is the C0 region, the horizontal plane of the small bending side vertex of the aortic arch to the horizontal plane of the aortic sinus is the C1 region, the horizontal plane of the aortic sinus to the horizontal plane of the right diaphragm vertex of the human body is the C2 region, the horizontal plane of the right diaphragm vertex of the human body to the horizontal plane of the proximal end of the celiac trunk artery opening is the C3 region, the horizontal plane of the proximal end of the celiac trunk artery opening to the horizontal plane of the distal end of the low renal artery opening is the C4 region, and the horizontal plane of the distal end of the low renal artery opening to the horizontal plane of the abdominal aortic bifurcation is the C5 region. In the above region division, the lower end plane of the C1 to C5 regions is often parallel to the direction of the spinal axis, therefore, the two-dimensional image obtained by CT scanning is perpendicular to the aortic axis, and can reflect the true aortic dissection parameters.

[0073] Referring to Figure 3 , the specific measurement and analysis process includes the following steps:

[0074] Step 1: For the six regions C0, C1, C2, C3, C4, C5 in the above partition, record the CT image cross-sectional position of the end point of each region, and define the corresponding CT image cross-sectional plane as N0, N1, N2, N3, N4, N5. Repeat steps 2 to 4 for each CT image cross-section to record the parameters of the aortic dissection of each cross-section.

[0075] Step 2: Identify the true lumen and the false lumen, and select the end points A and C of the long axis of the blood vessel in the cross-section.

[0076] Approximate the blood vessel as an ellipse, select the end point A of the long axis of the ellipse on the true lumen side, and select the end point C of the short axis of the ellipse on the false lumen side.

[0077] Connect A and C to form the long axis AC of the ellipse, and generate the midpoint O of the long axis AC as the center point of the ellipse. Then, generate the right ray in the horizontal plane as the x-axis and the ray in the OA direction as the y-axis.

[0078] Measure the length of the line segment AC as the maximum diameter of the blood vessel, and rotate the x-axis counterclockwise to make it coincide with the y-axis, with the x-axis as the positive direction. The angle of rotation is the true lumen spiral angle α.

[0079] Step 3: Select the end point B of the short axis of the blood vessel in the cross-section.

[0080] After the long axis of the ellipse is determined, draw a line through the center point of the ellipse perpendicular to the long axis to obtain the line on which the short axis lies. Select the end point B of the short axis of the ellipse.

[0081] According to symmetry, computer-aided generation of the other end point D of the short axis of the ellipse, connecting B and D to form the short axis BD of the ellipse, and generating an ellipse with A, B, C, and D as vertices.

[0082] Step 4: Select the end point E of the intimal flap and the intersection point G of the intimal flap and the long axis of the ellipse.

[0083] According to the shape and position of the intimal flap, select the end point E of the intimal flap, and select the intersection point G of the intimal flap and the long axis of the ellipse.

[0084] According to symmetry, computer-aided generation of the symmetric point F of E about the long axis AC of the ellipse, which is the other end point of the intimal flap. Generate a circular arc inside the ellipse with E, F, and G as endpoints, which is the intimal flap.

[0085] Computer-aided measurement of other geometric parameters:

[0086] The length of line segment AG is the true lumen diameter in the direction of the maximum diameter of the blood vessel.

[0087] The length of line segment GC is the false lumen diameter in the direction of the maximum diameter of the blood vessel.

[0088] The length of the circular arc EGF is the length of the inner membrane piece;

[0089] The length of the elliptical arc EAF is the length of the outer periphery of the true lumen;

[0090] The length of the elliptical arc EBCDF is the length of the outer periphery of the false lumen;

[0091] The area of the region AEGFA is the area of the true lumen;

[0092] The area of the region CBEGFDC is the area of the false lumen.

[0093] During the entire measurement process, only five points need to be manually selected on each CT image cross section, and the computer can automatically generate the boundary shape of the aortic dissection of the cross section.

[0094] According to the positions N0, N1, N2, N3, N4, N5 of the six CT image cross sections and the true lumen spiral angles α0, α1, α2, α3, α4, α5, the computer assists in calculating the true lumen spiral angle twist rate in the five regions, which is also a chiral parameter as the true lumen spiral angle, and the calculation formula is

[0095] The twist rate of the C1 region is (α1-α0) / (N1-N0)

[0096] The twist rate of the C2 region is (α2-α1) / (N2-N1)

[0097] The twist rate of the C3 region is (α3-α2) / (N3-N2)

[0098] The twist rate of the C4 region is (α4-α3) / (N4-N3)

[0099] The twist rate of the C5 region is (α5-α4) / (N5-N4)

[0100] According to the true lumen spiral angle twist rates of the five regions, the chirality morphology of the aortic dissection can be determined, as well as the chirality size.

[0101] It should be noted that during the calculation process, if the true lumen spiral angle rotation exceeds one turn, the corresponding α value should be increased by 360° to ensure the accuracy of the calculation.

[0102] S4: quantitatively analyzing the chirality morphology of the aortic dissection based on the measurement results.

[0103] Specifically, the method is used for quantitatively representing the chiral morphology of the aortic dissection (i.e., mainly the alpha angle and the true lumen spiral angle), and the quantitatively analyzing the chiral morphology of the aortic dissection based on the geometric morphology indexes provided by the measuring method, which helps the clinicians better understand the geometric morphology of the aortic dissection, helps the formulation of the surgical plan of the aortic dissection, helps reduce the occurrence of postoperative complications of the aortic dissection, and provides a theoretical basis for the improvement and optimization of the new aortic covered stent in the future.

[0104] The embodiment describes and measures the chiral morphology characteristics of the aortic dissection in the CT image cross section in a two-dimensional scale under a natural coordinate system based on the CT image features of the aortic dissection patient, and the method is simple to operate and has strong operability, is easy for the clinicians or technical personnel to understand and master, and can relatively accurately describe the change characteristics of the dissection spiral morphology.

[0105] Embodiment 2

[0106] Figure 7 is a schematic diagram of the system structure for quantitatively analyzing the chiral morphology of the aortic dissection. As shown in Figure 7 , the embodiment provides a system for quantitatively analyzing the chiral morphology of the aortic dissection, and the system comprises:

[0107] The acquisition module 501 is configured to acquire the enhanced CT angiography image of the aortic dissection patient in a lying state.

[0108] The division module 502 is configured to distinguish the true lumen and the false lumen of the aortic dissection based on the enhanced CT angiography image.

[0109] The measurement module 503 is configured to measure the chiral morphology of the dissection image to obtain a measurement result.

[0110] The analysis module 504 is configured to quantitatively analyze the chiral morphology of the aortic dissection based on the measurement result.

[0111] Preferably, the measurement of the chiral morphology of the dissection image by the measurement module 503 comprises:

[0112] The aorta in each CT section is approximated and simplified into an ellipse to determine the ellipse center point, the x-axis and the y-axis; wherein the x-axis represents a right ray in the horizontal plane perpendicular to the spine axis direction, which is also the main direction of the entire CT section, and the y-axis is an outward ray of the line on which the true lumen symmetry axis is located, and coincides with the line on which the major axis of the ellipse is located, and the direction of the y-axis changes with the case and the section.

[0113] Preferably, the measurement result comprises a quantitative index of the true lumen chiral morphology, and the quantitative index of the true lumen chiral morphology comprises a true lumen spiral angle, which is an included angle between the x-axis and the y-axis.

[0114] Preferably, the measurement result comprises a geometric quantitative index related to the selected region of the aortic dissection chiral morphology, and the geometric quantitative index comprises a maximum vessel diameter, a true lumen diameter in the direction of the maximum vessel diameter, a false lumen diameter in the direction of the maximum vessel diameter, an intimal flap length, a true lumen peripheral length, a false lumen peripheral length, a true lumen area, and a false lumen area.

[0115] Preferably, the division module 502 is further configured to:

[0116] The aortic structure is divided into six regions, C0, C1, C2, C3, C4, and C5, and the CT image cross-sectional positions of the lower end points of each region are recorded, and the cross-sectional layers of the CT images are defined as N0, N1, N2, N3, N4, and N5; the maximum vessel diameter is measured, and the x-axis is taken as the positive direction, and the x-axis is rotated counterclockwise to coincide with the y-axis, and the angle of rotation is the true lumen spiral angle α; according to the positions N0, N1, N2, N3, N4, and N5 of the six CT image cross-sections and the true lumen spiral angles α0, α1, α2, α3, α4, and α5, the true lumen spiral angle twist rates in the five regions are calculated, and the calculation formula is:

[0117] The twist rate of the C1 region is (α1-α0) / (N1-N0)

[0118] The twist rate of the C2 region is (α2-α1) / (N2-N1)

[0119] The twist rate of the C3 region is (α3-α2) / (N3-N2)

[0120] The twist rate of the C4 region is (α4-α3) / (N4-N3)

[0121] The twist rate of the C5 region is (α5-α4) / (N5-N4)

[0122] According to the true lumen spiral angle twist rates of the five regions, the chiral morphology and the chiral size of the aortic dissection are determined.

[0123] The specific implementation process of the functions implemented by each module in this embodiment 2 is the same as the implementation process of each step in embodiment 1, and will not be repeated here.

[0124] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the concept of the present application, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A method for quantitative analysis of aortic dissection chiral topography, characterized in that, The method comprises the following steps: S1: obtaining enhanced CT angiography images of a patient with aortic dissection in a lying state; S2: distinguishing the true lumen and the false lumen of the aortic dissection based on the enhanced CT angiography images; S3: measuring the chiral morphology of the dissection images to obtain measurement results; S4: quantitatively analyzing the chiral morphology of the aortic dissection based on the measurement results; the measurement of the chiral morphology of the dissection images comprises: approximating the entire aorta in each CT section to an ellipse to determine the center point, x-axis and y-axis of the ellipse; wherein the x-axis represents a right ray in the horizontal plane perpendicular to the spine axis direction, which is also the main direction of the entire CT section, and the y-axis is an outward ray of the straight line on which the true lumen symmetry axis is located, which coincides with the straight line on which the major axis of the ellipse is located, and the direction of the y-axis changes with the case and the section.

2. The method of claim 1, wherein, The measurement results include quantitative indicators of the true lumen chiral morphology, and the quantitative indicators of the true lumen chiral morphology include a true lumen spiral angle, which is the included angle between the x-axis and the y-axis.

3. The method of claim 2, wherein, The measurement results include geometric quantitative indicators related to the chiral morphology of the aortic dissection in the selected region, and the geometric quantitative indicators include the maximum diameter of the blood vessel, the true lumen diameter in the direction of the maximum diameter of the blood vessel, the false lumen diameter in the direction of the maximum diameter of the blood vessel, the intimal sheet length, the true lumen peripheral length, the false lumen peripheral length, the true lumen area and the false lumen area.

4. The method of claim 1, wherein, The method further comprises: partitioning the aortic structure into six regions C0, C1, C2, C3, C4 and C5, recording the CT image cross-sectional position of the lower end point of each region, and defining the cross-sectional layer of the CT image as N0, N1, N2, N3, N4 and N5; measuring the maximum diameter of the blood vessel, and rotating the x-axis counterclockwise to make it coincide with the y-axis, and the angle of rotation is the true lumen spiral angle α; according to the positions N0, N1, N2, N3, N4 and N5 of the six CT image cross sections and the true lumen spiral angles α0, α1, α2, α3, α4 and α5, the true lumen spiral angle twist rates in the five regions are calculated, and the calculation formula is: the twist rate of the C1 region=(α1-α0) / (N1-N0) the twist rate of the C2 region=(α2-α1) / (N2-N1) the twist rate of the C3 region=(α3-α2) / (N3-N2) the twist rate of the C4 region=(α4-α3) / (N4-N3) the twist rate of the C5 region=(α5-α4) / (N5-N4) According to the true lumen spiral angle twist rates of the five regions, the chiral morphology and the chiral size of the aortic dissection are determined.

5. A system for quantitative analysis of aortic dissection chiral topography, characterized in that, The system comprises: an acquisition module configured to obtain enhanced CT angiography images of a patient with aortic dissection in a lying state; a division module configured to distinguish the true lumen and the false lumen of the aortic dissection based on the enhanced CT angiography images; a measurement module configured to measure the chiral morphology of the dissection images to obtain measurement results; an analysis module configured to quantitatively analyze the chiral morphology of the aortic dissection based on the measurement results; the measurement of the chiral morphology of the dissection images by the measurement module comprises: The aorta in each CT section is approximated and simplified as an ellipse, and the center point, x-axis and y-axis of the ellipse are determined; wherein the x-axis represents a right ray in a horizontal plane perpendicular to the direction of the spine axis, and is also the main direction of the CT section, and the y-axis is an outward ray of a line on which a true lumen symmetry axis is located, and coincides with a line on which a long axis of the ellipse is located, and the direction of the y-axis changes with the case and the section.

6. The system of claim 5, wherein, The measurement result includes a quantitative index of the true lumen chiral morphology, and the quantitative index of the true lumen chiral morphology includes a true lumen spiral angle, which is an included angle between the x-axis and the y-axis.

7. The system of claim 6, wherein, The measurement result includes a geometric quantitative index related to the chiral morphology of the selected region aortic dissection, and the geometric quantitative index includes a maximum vessel diameter, a true lumen diameter in the direction of the maximum vessel diameter, a false lumen diameter in the direction of the maximum vessel diameter, an intimal flap length, a true lumen peripheral length, a false lumen peripheral length, a true lumen area and a false lumen area.

8. The system of claim 6, wherein, The division module is further configured to: The aorta structure is divided into six regions C0, C1, C2, C3, C4 and C5, and the CT image cross-sectional positions of the lower end points of each region are recorded, and the cross-sectional layers of the CT image are defined as N0, N1, N2, N3, N4 and N5; the maximum vessel diameter is measured, and the x-axis is taken as a positive direction, and the x-axis is rotated counterclockwise to coincide with the y-axis, and the angle of rotation is a true lumen spiral angle α; according to the positions N0, N1, N2, N3, N4 and N5 of the six CT image cross sections and the true lumen spiral angles α0, α1, α2, α3, α4 and α5, the true lumen spiral angle twist rates in the five regions are calculated, and the calculation formula is: The twist rate of the C1 region is (α1-α0) / (N1-N0) The twist rate of the C2 region is (α2-α1) / (N2-N1) The twist rate of the C3 region is (α3-α2) / (N3-N2) The twist rate of the C4 region is (α4-α3) / (N4-N3) The twist rate of the C5 region is (α5-α4) / (N5-N4) According to the true lumen spiral angle twist rates of the five regions, the chiral morphology and the chiral size of the aortic dissection are determined.

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