Angiography method for arteriovenous differentiation after death

Abstract

The invention discloses a post-death arteriovenous differentiation angiography method, which greatly improves the diagnostic value of post-death angiography, selects two different fat-soluble angiography materials and stores the two different fat-soluble angiography materials in different containers to ensure that the two fat-soluble angiography materials are not mixed and polluted; carrying out corpse surface inspection and whole body tomography on the corpse to obtain a plain-scan image; filling the angiography material X into the arterial system of the corpse, and after filling, performing whole-body tomography on the corpse by using CT (Computed Tomography) equipment; filling the contrast material Y into the venous system of the corpse, and after filling is completed, performing whole-body tomography on the corpse by using CT (Computed Tomography) equipment; performing post-processing on the acquired image by using MIP and 3D VR technologies, observing the image of the artery system of the corpse acquired in S3, and focusing on whether the artery of the important part of the corpse has a disease or injury or not; s4, observing the vein system image of the corpse obtained in the step S4, and focusing on whether obvious trauma exists on the body surface of the corpse; the method can be widely applied to medical related fields.

Description

Technical Field

[0001] The invention relates to a post-mortem arteriovenous differentiated angiography method, belonging to the technical fields of medical imaging technology, forensic pathology and medicine. Background Art

[0002] With the rapid development of imaging technology, postmortem angiography has gradually become a key technology in forensic science, used to determine the cause of death, pathological changes, and evaluate the condition of the vascular system. The core of postmortem angiography technology is to inject contrast material into the vascular system of the corpse, so as to show the morphology and structure of the blood vessels in the image.

[0003] Since blood circulation stops after death and there is no natural flow medium in the blood vessels, the selection and application of contrast materials have become a top priority in the implementation of the technology. At present, there are many types of materials used for cadaver angiography, which can be roughly divided into the following categories: microgel or agar preparations, microparticle water-soluble preparations, water-soluble preparations, oily preparations, mixed materials, air and magnetic nanomaterials. These materials show their own unique contrast effects through different chemical compositions and physical properties. For example, fat-soluble materials can stay stably in blood vessels and occlude the microvascular system without penetrating into the tissues around the cadaver blood vessels; magnetic nanomaterials can achieve more precise image positioning through the control of external magnetic fields.

[0004] Although many advances have been made in contrast materials and technologies in the field of postmortem angiography, existing cadaveric angiography schemes still have many limitations in practical application, which restricts their effectiveness and widespread promotion.

[0005] First, although many contrast materials have been studied in the field of postmortem imaging, the current method is still to use the same contrast material in the arterial and venous systems, which cannot effectively distinguish between the two in imaging, limiting the precise positioning and analysis of vascular lesions and injuries; when performing imaging on corpses of different natures, arteries and veins often have different optimal imaging schemes due to differences in anatomical structure and injury characteristics. At the same time, there are also challenges in the post-processing stage of these images. Some image processing methods have difficulty in accurately identifying and segmenting mixed vascular structures, especially in diseased or damaged vascular areas.

[0006] In summary, although the current postmortem angiography technology has played an important role in forensic science, it still has many limitations in material selection, technical implementation and image processing, and further research and technological innovation are urgently needed to overcome these challenges. Summary of the invention

[0007] The present invention overcomes the shortcomings of the prior art and provides a post-mortem arteriovenous differentiated angiography method, which greatly improves the diagnostic value of post-mortem angiography and is not only suitable for cadaver vascular imaging in forensic medicine, but also can be applied to non-medical fields such as animal research, teaching, and laboratory simulation.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a post-mortem arteriovenous differentiated angiography method, which is implemented according to the following steps: S1. Select two different fat-soluble contrast materials, namely contrast material X and contrast material Y; The two materials are stored in separate containers to ensure that mixing and contamination do not occur; S2. Perform a surface examination and whole-body tomography scan of the corpse to obtain plain scan images; S3. Performing systemic vascular perfusion on the corpse: perfusing contrast material X into the arterial system of the corpse. After the perfusion is completed, a whole-body tomography scan is performed on the corpse using a CT device; S4, injecting contrast material Y into the venous system of the corpse, and after the injection is completed, performing a whole-body tomography scan of the corpse using a CT device; S5. Use MIP and 3D VR technology to post-process the acquired images, observe the images of the cadaver arterial system acquired in S3, and focus on whether there are diseases or injuries in the arteries of important parts of the cadaver; observe the images of the cadaver venous system acquired in S4, and focus on whether there are obvious external injuries on the body surface of the cadaver.

[0009] Preferably, the contrast material X and the contrast material Y differ in at least one property of viscosity, polarity and CT value.

[0010] Preferably, the contrast material X differs from the contrast material in at least one property of viscosity and CT value.

[0011] Preferably, the viscosity and CT value of the contrast material for arterial injection are greater than those of the contrast material for intravenous injection.

[0012] Preferably, the viscosity and CT value of the contrast material for arterial injection are 35-45 mPa·s and 550-650 HU, respectively, and the viscosity and CT value of the contrast material for intravenous injection are 20-25 mPa·s and 300-350 HU, respectively.

[0013] Preferably, the contrast material X has a CT value of 650 HU and a viscosity of 35 mPa·s; the contrast material Y has a CT value of 300 HU and a viscosity of 20 mPa·s.

[0014] Compared with the prior art, the present invention has the following beneficial effects.

[0015] The existing cadaver angiography injects the same contrast material into the arteries and veins of the cadaver, and then scans the cadaver with imaging equipment. This examination method cannot distinguish arteries and veins on the same image. The arteriovenous differentiated angiography method uses two contrast materials with different physical and chemical properties in the arteries and veins. Compared with the traditional method, it has the following advantages: In terms of cadaveric image quality and subsequent diagnosis, arteriovenous differential angiography can bring higher quality images and clearer diagnosis.

[0016] 1. Enhance the clarity of vascular images: Since contrast materials are not limited by toxicity and metabolic kinetics that need to be considered in the case of living bodies, high CT value contrast materials can be used to enhance the visualization effect of the arterial system. However, the number of venous systems is greater than that of arteries, and the average lumen diameter is also thicker. The use of high CT value contrast materials in the venous system will lead to unclear boundaries between blood vessels and surrounding tissues, affecting the visualization effect of the image.

[0017] In contrast, the differentiated arteriovenography strategy has significant advantages. By using different contrast materials for arteries and veins, the boundaries between veins and other veins or anatomical structures can be clearly distinguished to reduce confusion. Differential angiography not only enhances the visualization of blood vessels, but also helps to accurately identify the contours and paths of blood vessels, greatly improving the clarity and visual effect of the image.

[0018] 2. Accurately locate vascular damage: In terms of vascular damage location, in traditional cadaver angiography, the use of the same contrast material in the arteriovenous system may make it impossible to accurately distinguish the arterial and venous sources of the leaking contrast material; at the same time, the leaking contrast material may accumulate around the blood vessels, thereby covering up the vascular rupture, making it more difficult to identify the location of the injury. In contrast, the differential angiography technology uses low CT value contrast materials, which can more clearly define the boundary between the leakage area and the surrounding tissue, and clearly distinguish the source of the contrast material by identifying the image components of the leakage area, thereby more accurately locating vascular damage and further improving the accuracy and reliability of injury location.

[0019] 3. Precision and individualization of examination plans: Different corpses have different vascular characteristics. Differentiated angiography plans can be used for corpses in different states to provide more individualized examination plans. For example, when performing angiography on a newborn corpse, due to the strong permeability of its blood vessels and the fragility and rupture of its veins, it is more appropriate to use a lower viscosity fat-soluble contrast agent in intravenous perfusion.

[0020] In the analysis and processing of cadaver angiography images, the arteriovenous differentiation angiography method is conducive to the distinction of anatomical positions and reduces the corresponding errors when post-processing images.

[0021] 1. Maximum Intensity Projection (MIP) post-processing: In the MIP post-processing of complex vascular systems, the traditional cadaver angiography shows mixed displays of multiple blood vessels and tissues, making it difficult to accurately select layer thickness, layer spacing, and angles. Differential angiography significantly improves the distinction between blood vessels and the separation of blood vessels from the background. The contours and paths of blood vessels on MIP images are clearer, and the continuity and diagnostic value of the image are significantly enhanced.

[0022] 2. Post-processing of digital subtraction technology: Traditional digital subtraction technology relies on subtraction processing between images obtained before and after the injection of contrast material into the blood vessels to highlight the vascular structure and remove background tissue. Since the corpse does not move, its angiography images are particularly suitable for digital subtraction processing; at the same time, separate perfusion of arteries and veins can generate independent venous and arterial images through subtraction technology. However, the arteries and veins of traditional cadaver angiography are prone to overlap, affecting the execution of the subtraction algorithm. Arteriovenous differential angiography improves the distinction between arteries and veins in images, reduces artifacts, and significantly improves the accuracy and reliability of subtraction.

[0023] 3. Post-processing of image editing: In the one-click bone and bed board removal process, the CT values ​​of blood vessels, bones and bed boards in traditional cadaver angiography are similar, and complex automatic segmentation and manual adjustment are prone to accidentally damage important vascular structures. Arteriovenous differential angiography gives blood vessels different CT values, simplifies the calculation and editing process, and improves the accuracy and efficiency of image editing. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with specific embodiments.

[0025] The arteriovenous differential angiography method described in the post-mortem arteriovenous differential angiography method of the present invention refers to injecting two imaging materials with different properties into the arteries and veins respectively.

[0026] The two different contrast materials are preferably two contrast materials that differ in one or more properties of viscosity, polarity, and CT value.

[0027] The two contrast materials having differences in one or more properties of viscosity, polarity, and CT value are preferably two contrast materials having differences in one or both properties of viscosity and CT value.

[0028] The two contrast materials having differences in one or both of viscosity and CT value are preferably two contrast materials having differences in both of viscosity and CT value.

[0029] The two contrast materials having different properties in terms of viscosity and CT value are preferably such that the viscosity and CT value of the contrast material for arterial injection are greater than those of the contrast material for intravenous injection.

[0030] The viscosity and CT value of the contrast material for arterial injection are greater than those for intravenous injection. Preferably, the viscosity and CT value of the contrast material for arterial injection are 35-45 mPa·s and 550-650 HU, respectively, and the viscosity and CT value of the contrast material for intravenous injection are 20-25 mPa·s and 300-350 HU, respectively.

[0031] Implementation Cases: S1. Select two fat-soluble contrast materials, namely contrast material X and contrast material Y. The CT value of contrast material X is 650HU and the viscosity is 35mPa·s; the CT value of contrast material Y is 300HU and the viscosity is 20mPa·s. The two materials are stored in different containers to ensure that they are not mixed or contaminated.

[0032] S2. Perform a surface examination and whole-body tomography scan of the corpse to obtain plain scan images; S3. Perform systemic vascular perfusion on the corpse: perfuse contrast material X into the arterial system of the corpse. After the perfusion is completed, use CT equipment to perform a whole-body tomography scan on the corpse.

[0033] S4. Infuse contrast material Y into the venous system of the corpse. After the infusion is completed, use a CT device to perform a whole-body tomography scan of the corpse.

[0034] S5. Use MIP and 3D VR technology to post-process the acquired images, observe the images of the cadaver arterial system acquired in S3, and focus on whether there are diseases or injuries in the arteries of important parts of the cadaver; observe the images of the cadaver venous system acquired in S4, and focus on whether there are obvious external injuries on the body surface of the cadaver.

[0035] The present invention has been described in detail above in conjunction with the embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the field without departing from the purpose of the present invention.

Claims

1. A post-mortem arteriovenous differential angiography method, characterized in that: Follow these steps to implement: S1. Select two different fat-soluble contrast materials, namely contrast material X and contrast material Y; The two materials are stored in separate containers to ensure that mixing and contamination do not occur; S2. Perform a surface examination and whole-body tomography scan of the corpse to obtain plain scan images; S3. Performing systemic vascular perfusion on the corpse: perfusing contrast material X into the arterial system of the corpse. After the perfusion is completed, a whole-body tomography scan is performed on the corpse using a CT device; S4, injecting contrast material Y into the venous system of the corpse, and after the injection is completed, performing a whole-body tomography scan of the corpse using a CT device; S5. Use MIP and 3D VR technology to post-process the acquired images, observe the images of the cadaver arterial system acquired in S3, and focus on whether there are diseases or injuries in the arteries of important parts of the cadaver; observe the images of the cadaver venous system acquired in S4, and focus on whether there are obvious external injuries on the body surface of the cadaver.

2. A post-mortem arteriovenous differentiated angiography method according to claim 1, characterized in that: The contrast material X and the contrast material Y differ in at least one property of viscosity, polarity, and CT value.

3. A post-mortem arteriovenous differentiated angiography method according to claim 2, characterized in that: The contrast material X differs from the contrast material in at least one property of viscosity and CT value.

4. A post-mortem arteriovenous differentiated angiography method according to claim 1, characterized in that: The viscosity and CT value of contrast materials used for arterial injection are greater than those used for intravenous injection.

5. A post-mortem arteriovenous differentiated angiography method according to claim 1, characterized in that: The viscosity and CT value of contrast materials for arterial injection are 35-45 mPa·s and 550-650 HU, respectively; the viscosity and CT value of contrast materials for intravenous injection are 20-25 mPa·s and 300-350 HU, respectively.

6. A post-mortem arteriovenous differential angiography method according to claim 1, characterized in that: The contrast material X has a CT value of 650 HU and a viscosity of 35 mPa·s; the contrast material Y has a CT value of 300 HU and a viscosity of 20 mPa·s.