Coronary microcirculation disturbance examination technology in non-occlusive coronary disease

Abstract

The invention relates to a coronary microcirculation disturbance examination technology in non-occlusive coronary diseases, and aims to objectively evaluate the myocardial ischemia degree of angina pectoris patients without occlusive coronary diseases and quantify the myocardial ischemia range caused by microcirculation disturbance through a load dynamic myocardial perfusion imaging (MPI) technology. Siemens third-generation double-source CT is adopted, a coarse pitch scanning mode is utilized, a one-stop CCTA combined MPI technology is achieved, the problem that the radiation dosage is too high is solved, and meanwhile the detection rate of myocardial ischemia is increased. Indexes such as myocardial blood flow (MBF), myocardial blood volume (MBV), time of arrival (TTP), coronary artery blood flow reserve (CFR) and the like of angina pectoris patients and healthy volunteers are compared, and changes of myocardial ischemia areas are objectively evaluated. The degree and range of microcirculation disturbance are quantitatively evaluated, and an infarction region and an ischemic region are identified. Quantitative evaluation is carried out on coronary artery microcirculation of the angina pectoris patient in clinical work, and a basis is provided for early intervention.

Description

Technical Field

[0001] The present invention relates to the technical field of cardiovascular disease assessment, and in particular to a technique for detecting coronary microcirculation disorders in patients without occlusive coronary artery disease. Background Art

[0002] Coronary heart disease is a common cardiovascular disease. Coronary heart disease is one of the main causes of human death and seriously endangers human physical and mental health. For a long time, it has been believed that epicardial coronary artery obstruction is the pathogenesis of angina pectoris and myocardial ischemia. However, clinically, many patients with typical angina symptoms have no obvious stenosis during coronary angiography (coronary artery stenosis <50%). In the early days, people called it heart syndrome X, and believed that such symptoms had a good prognosis. In recent years, it has been found that this symptom is mainly caused by coronary microcirculatory dysfunction (coronary microvascular dysfunction, CMD), and this type of angina is clinically called microvascular angina.

[0003] Coronary microcirculation refers to the microcirculatory system composed of arterioles, capillaries and tiny veins with a diameter of less than 150μm. It refers to the blood circulation between arterioles and venules. The heart uses this to achieve material exchange between blood and tissues and ensure the normal functional activities of the myocardium. According to different clinical symptoms and pathogenesis, coronary microcirculatory disorders are divided into the following four types: coronary microcirculatory disorders without cardiomyopathy or occlusive coronary artery disease; coronary microcirculatory disorders with cardiomyopathy; coronary microcirculatory disorders with occlusive coronary artery disease; idiopathic coronary microcirculatory disorders. Among them, idiopathic coronary microcirculatory disorders include iatrogenic coronary microcirculatory disorders and coronary microcirculatory disorders after heart transplantation.

[0004] At present, CMD is receiving more and more attention. In addition to obstructive coronary artery disease and vasospastic disease, CMD is gradually considered to be another mechanism of angina pectoris and myocardial ischemia. Studies have found that the incidence of adverse cardiac events in patients with CMD is very high. In recent years, people have a certain understanding of the pathophysiological mechanism, evaluation and diagnosis methods, and clinical treatment methods of CMD. At present, there is no clear evaluation and diagnostic standard for CMD in clinical practice, and there are also differences in its drug treatment. It can be observed that a considerable number of patients with refractory angina pectoris but negative coronary angiography have not received effective treatment in clinical practice.

[0005] With the development of medical technology in recent years, great progress has been made in the diagnosis and treatment of myocardial infarction. However, the evaluation of microcirculatory disorders has high requirements for microcirculatory detection technology and limited accuracy. How to accurately evaluate myocardial microcirculatory perfusion has become a concern for clinical physicians. Currently, there are different detection methods such as contrast evaluation of myocardial perfusion, radionuclide myocardial perfusion imaging, myocardial magnetic resonance imaging (MRI), coronary microcirculatory resistance index (IMR), and stress dynamic CT myocardial perfusion imaging (MPI).

[0006] TIMI blood flow grading in coronary angiography and blood flow imaging can observe the state of myocardial microcirculation perfusion by observing the perfusion of contrast agent into the myocardium and the clearance time of contrast agent. It can indirectly reflect the function of coronary microcirculation, but this method has differences in subjective judgment of the examiner and is a qualitative analysis. Clinically, it has also been found that patients with TIMI blood flow of grade III still have low-level hypoperfusion of myocardial tissue. Corrected TIMI frame counts (CTFC) can semi-quantitatively detect epicardial coronary artery blood flow, detect the integrity of coronary microvessels and judge its prognosis. Coronary artery blood flow reserve fraction (FFR) is a specific indicator for evaluating epicardial coronary artery stenosis. It is mainly used clinically to guide whether critical coronary artery stenosis requires interventional treatment and to judge whether PCI surgery is ideal. Myocardial contrast echocardio-graphy (MCE) can intuitively determine the phenomenon of no coronary reflow after PCI treatment, can show the area and location of poor myocardial microcirculatory perfusion, and preliminarily screen patients with no reflow or slow reflow, but the diagnosis still has certain limitations. Radionuclide myocardial perfusion imaging is used to diagnose ischemic heart disease and evaluate the efficacy of reperfusion therapy. It can specifically reflect the coronary blood flow reserve function and myocardial microcirculatory perfusion status for patients with microvascular lesions without severe stenosis of CAG, and has high specificity. However, it is expensive, has low spatial resolution, and cannot show ventricular wall motion, so it is rarely used in clinical practice. Myocardial MRI evaluates the state of myocardial microcirculation through delayed enhancement scanning and imaging of myocardial perfusion, which can better reflect the degree of damage to epicardial large vessels and microcirculation. It is currently recognized as an effective method for quantitatively evaluating the microcirculatory status in chest pain. However, the cost is relatively high, and the contraindications of MRI limit the application and postoperative follow-up of some patients. Stress dynamic CT myocardial perfusion imaging (MPI) has been widely studied in recent years, but its actual application is limited due to factors such as large radiation dose and limited coverage. In addition, the research mainly involves microcirculatory disorders caused by occlusive coronary artery disease and the evaluation of microcirculatory disorders after stent implantation. There are few studies on angina pectoris patients without cardiomyopathy and occlusive coronary artery disease.

[0007] This study uses the hardware update of Siemens' third-generation dual-source CT, adopts a large pitch scanning method, and applies one-stop CCTA combined with stress dynamic CT myocardial blood perfusion imaging (MPI). In addition to obtaining perfusion images, CTA images can also be obtained, and whole-heart perfusion imaging can be performed, which can effectively solve the problem of excessive radiation dose. At the same time, this study compares and analyzes stress dynamic myocardial perfusion imaging in patients with angina pectoris without occlusive coronary artery disease with normal healthy people, and objectively evaluates the changes in myocardial ischemic areas by measuring myocardial blood flow (MBF), myocardial blood volume (MBV), time to peak (TTP), and coronary blood flow reserve (CFR), and quantitatively evaluates the degree and range of microcirculatory disorders, providing an objective basis for early clinical intervention and rehabilitation. Summary of the invention

[0008] In order to solve the problems of the prior art, the present invention provides a technique for detecting coronary microcirculation disorders in patients with non-occlusive coronary artery disease.

[0009] In order to solve the above technical problems, the present invention is implemented by the following technical solutions: A technique for detecting coronary microcirculation disorders in patients without occlusive coronary artery disease, comprising the following steps:

[0010] Step S1: Scanning the patient using a Siemens third-generation dual-source CT scanner, which has a large pitch scanning mode and can perform one-stop CCTA (coronary CT angiography) combined with stress dynamic CT myocardial perfusion imaging (MPI);

[0011] Step S2: Before scanning, the ATP (adenosine triphosphate) dose is calculated according to the patient's body weight, and ATP is continuously intravenously pumped at a dose of 0.16 mg / (kg·min) at a uniform rate, while the patient's heart rate, blood pressure and symptom changes are monitored throughout the process;

[0012] Step S3: 3 to 4 minutes after the injection of ATP, 44 ml of contrast agent was injected at a rate of 5.5 ml / s, followed by 60 ml of saline at the same rate to ensure an iodine injection rate of 2.0 g / s for 8 seconds;

[0013] Step S4: After the contrast agent is injected, the MPI scan is started 5 seconds later. The scanning range covers the entire left ventricle. The cradle bed mode is used for continuous dynamic scanning. The end-systolic phase (250ms after the R wave) is completely collected once every 2 cardiac cycles. 1 to 2 minutes before the scan, the patient sprays 0.1 mg of nitroglycerin sublingually.

[0014] Step S5: At the same time, CCTA scanning is performed, with the scanning range from 1 cm below the tracheal bifurcation to the diaphragmatic surface of the heart, using a prospective large pitch (Turbo Flash) scanning mode, with tube voltage automatically selected, to complete the whole heart image acquisition within a single cardiac cycle;

[0015] Step S6: reconstruct the image using the advanced simulation iterative reconstruction (ADMIRE) technique to obtain the MPI image and CCTA image;

[0016] Step S7: By measuring parameters such as myocardial blood flow (MBF), myocardial blood volume (MBV), time to peak pressure (TTP), and coronary flow reserve (CFR), the myocardial perfusion conditions of angina pectoris patients and healthy volunteers are compared and analyzed to objectively evaluate the changes in the myocardial ischemic area and quantitatively assess the degree and scope of microcirculatory disorders.

[0017] In this implementation, it mainly includes stress dynamic CT myocardial perfusion imaging (MPI)

[0018] Load induction: By pumping drugs such as ATP into the vein, the myocardium is put under load, increasing myocardial oxygen consumption and thus inducing myocardial ischemia.

[0019] CT scan: Utilize the high temporal resolution and dynamic enhanced scanning technology of Siemens' third-generation dual-source CT to perform continuous dynamic scanning of the myocardium and obtain myocardial blood perfusion information at different time points.

[0020] Image reconstruction and analysis: The image is reconstructed using the Advanced Simulation Iterative Reconstruction Technology (ADMIRE) to improve image quality. The image is then analyzed using professional software to measure indicators such as myocardial blood flow (MBF), myocardial blood volume (MBV), time to peak (TTP), and coronary flow reserve (CFR) to assess changes in myocardial ischemic areas and the degree of microcirculatory disorders.

[0021] One-stop CCTA combined with MPI scanning

[0022] CCTA: Coronary CT angiography (CCTA) is used to evaluate the morphological information of the coronary arteries, such as the degree of coronary stenosis and the nature of plaques.

[0023] MPI: Stress dynamic CT myocardial perfusion imaging (MPI) is used to evaluate myocardial blood perfusion information, such as myocardial blood flow, myocardial blood volume, peak time, etc.

[0024] One-stop scanning: CCTA and MPI images can be acquired simultaneously through one injection, realizing the complementary advantages of the two examinations and completing a complete evaluation of coronary artery lesions from morphology to functionality.

[0025] Technical features and advantages

[0026] High temporal resolution: Siemens' third-generation dual-source CT has high temporal resolution and can accurately capture myocardial blood perfusion information at different time points.

[0027] Low radiation dose: The large pitch scanning method and automatic tube current adjustment technology greatly reduce the radiation dose and protect the patient's safety.

[0028] One-stop scanning: simultaneous acquisition of coronary artery morphology information and myocardial blood perfusion information, improving the accuracy and efficiency of diagnosis.

[0029] Non-invasive examination: Stress dynamic CT myocardial blood perfusion imaging is a non-invasive examination that is fast, low-cost, and has few restrictions on the scope of applicability.

[0030] In some specific embodiments, the CT detector collimation of Siemens' third-generation dual-source CT scanner is 96×2×0.6mm, the MPI technology adopts the cradle bed mode and z-axis flying focus technology, the detector z-axis coverage width is 10.5cm, the gantry rotation speed is 250ms / turn, and the single-sector time resolution is 66ms.

[0031] In some specific embodiments, both MPI and CCTA scans use automatic tube current adjustment technology (CAREDose4D, Siemens) to optimize radiation dose.

[0032] In some specific embodiments, the Kernel value of MPI image reconstruction is Qr36, the layer thickness is 3 mm, and the layer spacing is 2 mm; the Kernel value of CCTA image reconstruction is Bv36, the layer thickness is 0.75 mm, and the layer spacing is 0.5 mm.

[0033] In some specific embodiments, the method is suitable for the assessment of coronary microcirculation disorders in patients with angina pectoris without occlusive coronary artery disease, and comparative analysis with normal healthy people is performed through load dynamic myocardial perfusion imaging, providing an objective basis for early clinical intervention and rehabilitation.

[0034] The beneficial effects of the present invention are:

[0035] 1. The present invention performs load dynamic myocardial perfusion imaging on patients with angina pectoris without occlusive coronary artery disease and compares and analyzes them with normal healthy people. By measuring myocardial blood flow (MBF), myocardial blood volume (MBV), time to peak (TTP), and coronary flow reserve (CFR), the degree of myocardial ischemia is objectively evaluated, and the scope of myocardial ischemia caused by microcirculatory disorders is quantitatively evaluated. The scope of infarction area and ischemic area can also be identified, providing an objective basis for early clinical intervention and rehabilitation;

[0036] 2. By using Siemens third-generation dual-source CT for large-pitch MPI scanning, the coverage area is wide and the radiation dose is greatly reduced. In addition, by using one-stop CCTA combined with MIP scanning, CCTA and perfusion images can be obtained at the same time in one scan, reducing the amount of contrast agent used by patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the organizational implementation steps of Embodiment 1 and Embodiment 2 of the present invention.

[0038] Figure 2 It is a schematic diagram of coronary CTA and stress myocardial perfusion of volunteers according to the first embodiment of the present invention.

[0039] Figure 3 It is a schematic diagram of coronary CTA and stress myocardial perfusion of a patient according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0041] Example 1 Figure 1 and Figure 2 As shown:

[0042] Research background and purpose:

[0043] The purpose of this study is to measure myocardial blood flow (MBF), myocardial blood volume (MBV), time to peak pressure (TTP) and coronary flow reserve (CFR) in healthy volunteers through stress dynamic myocardial perfusion imaging (MPI) technology, to establish a reference range for normal myocardial perfusion parameters, and to provide a comparative benchmark for subsequent patient studies.

[0044] Research Methodology:

[0045] Study subjects: Female, 45 years old, healthy volunteers without high risk factors for cardiovascular disease.

[0046] Equipment and technology: Siemens third-generation dual-source CT is used, large pitch scanning is applied, and MPI and CCTA technology are combined in one stop. MPI scanning uses cradle bed mode and z-axis flying focus technology to ensure high resolution and low radiation dose.

[0047] Inspection process:

[0048] The subjects were fasting and avoided caffeine and other substances that may affect myocardial perfusion.

[0049] Install an ECG monitor to monitor heart rate and blood pressure.

[0050] ATP was continuously infused intravenously at a constant rate of 0.16 mg / (kg·min), and changes in the patient's symptoms were monitored.

[0051] After contrast agent injection, MPI scanning was started to cover the entire left ventricle and continuously acquire dynamic data.

[0052] Subsequently, CCTA scanning was performed using a prospective large-pitch scanning mode, automatic tube voltage selection, and contrast agent automatic tracking triggering technology.

[0053] Data analysis: Professional software was used to reconstruct images, measure MBF, MBV, TTP, CFR and other indicators, conduct statistical analysis, and establish a normal reference value range.

[0054] Results: No obvious abnormal changes were found in coronary CTA and stress myocardial perfusion.

[0055] significance:

[0056] Providing normal control data for MPI examination of patients with angina pectoris helps to accurately assess the degree of myocardial ischemia and microcirculation disorders in patients.

[0057] Example 2 Figure 1 and Figure 3 Shown:.

[0058] Research background and purpose:

[0059] The aim is to evaluate myocardial perfusion abnormalities in patients with angina pectoris and quantify the degree of microcirculatory disturbances by comparing the results of stress dynamic myocardial perfusion imaging (MPI) between patients with angina pectoris and healthy volunteers, so as to provide a basis for early clinical intervention.

[0060] Research Methodology:

[0061] Research subjects: 31-year-old male patients with angina pectoris.

[0062] Equipment and technology: Same as in Example 1, using Siemens third-generation dual-source CT for one-stop MPI and CCTA examination.

[0063] Inspection process:

[0064] Both the patient group and the healthy group were examined according to the examination process in Example 1.

[0065] Special attention was paid to the symptom changes of the patient group during ATP injection, and the changes in electrocardiogram and blood pressure were recorded.

[0066] Data Analysis:

[0067] Measure and record MBF, MBV, TTP, CFR and other indicators.

[0068] The differences between the patient group and the control group were compared, and the characteristics of abnormal myocardial perfusion in patients with angina pectoris were analyzed.

[0069] The ability of MPI in differentiating infarcted and ischemic areas was evaluated.

[0070] Results: Coronary CTA showed myocardial bridging of the left anterior descending artery with compression of the coronary artery wall during systole. Stress myocardial perfusion showed a significant decrease in myocardial blood flow in the anterior wall of the left ventricle and the middle-base of the ventricular septum.

[0071] significance:

[0072] Provide a quantitative assessment method for abnormal myocardial perfusion in patients with angina pectoris to guide early clinical intervention.

[0073] Promote the application of MPI technology in the early diagnosis of coronary heart disease and the assessment of microcirculatory disorders, and improve the level of diagnosis and treatment.

[0074] In summary: The objectives and main research contents of the project plan.

[0075] 1. Main objectives

[0076] By exploring the abnormal manifestations of coronary microcirculation by MPI examination technology in patients with angina pectoris who do not have cardiomyopathy and occlusive coronary artery disease, and comparing and analyzing the myocardial blood flow (MBF), myocardial blood volume (MBV), time to peak (TTP), coronary flow reserve (CFR) and other parameters between patients with angina pectoris and healthy volunteers, we can objectively evaluate the changes in myocardial ischemic areas, quantitatively assess the degree and scope of microcirculatory disorders, and distinguish between infarcted and ischemic areas. This will provide a basis for quantitative evaluation of coronary microcirculation in patients with angina pectoris in clinical work and provide a basis for early intervention.

[0077] 2. Research and development content

[0078] This project uses the hardware update of Siemens' third-generation dual-source CT, adopts a large pitch scanning method, and adopts a one-stop CCTA combined with MPI technology. In addition to obtaining perfusion images, it can also extract CTA images, which can perform whole-heart perfusion imaging and can better solve the problem of excessive radiation dose. At the same time, this study focuses on the load dynamic myocardial perfusion imaging of patients with angina pectoris without occlusive coronary artery disease and the normal healthy population for comparative analysis. By measuring myocardial blood flow (MBF), myocardial blood volume (MBV), time to peak (TTP), and coronary blood flow reserve (CFR), the changes in myocardial ischemic areas are objectively evaluated, the degree and range of microcirculatory disorders are quantitatively evaluated, and the infarction area and ischemic area can be distinguished, providing an objective basis for early clinical prevention and treatment.

[0079] 3. Key technical aspects of the project (difficulties and innovations)

[0080] The third-generation dual-source CT scan of Siemens was used: the CT detector was collimated to 96×2×0.6mm, the MPI technology used the cradle bed mode and z-axis flying focus technology, the detector z-axis coverage width was 10.5cm, the gantry rotation speed was 250ms / circle, and the single-sector time resolution was 66ms. Both MPI and CCTA scanning used automatic tube current adjustment technology (CAREDose 4D, Siemens). Image reconstruction used advanced modeled iterative reconstruction (ADMIRE) technology. The ATP dose was calculated according to the patient's body weight, and ATP was continuously intravenously pumped at a uniform rate of 0.16mg / (kg·min). The patient's heart rate, blood pressure and symptom changes were monitored throughout the process. CT contrast agent was injected 3-4min after ATP injection (44ml of contrast agent was injected at 5.5ml / s, followed by 60ml of normal saline at 5.5ml / s, to ensure an iodine injection rate of 2.0g / s for 8s). The MPI scan was started 5s after contrast agent injection: the scanning range covered the entire left ventricle, and continuous dynamic scanning was performed in cradle bed mode. The end-systolic period (250ms after R wave) was completely collected once every 2 cardiac cycles. Nitroglycerin (0.1mg) was sprayed sublingually 1-2min before scanning. The CCTA scanning range was from 1cm below the tracheal bifurcation to the diaphragmatic surface of the heart. The prospective large pitch (Turbo Flash) scanning mode was used, and the tube voltage was automatically selected (CarekV on). The whole heart image was collected within a single cardiac cycle: before scanning, the RR interval of 30% was triggered for patients with heart rate >70bpm, and the RR interval of 65% was triggered for patients with heart rate ≤70bpm; the contrast agent automatic tracking trigger technology was used, and the trigger point was set at the root of the ascending aorta. After reaching the trigger threshold (100HU), the CCTA scan was automatically started 4s later. The MPI image reconstruction kernel value is Qr36, the layer thickness is 3mm, and the layer spacing is 2mm; the CCTA image reconstruction kernel value is Bv36, the layer thickness is 0.75mm, and the layer spacing is 0.5mm.

[0081] Difficulty: The judgment of subendocardial myocardial ischemia may be affected by the volume effect, resulting in possible deviation in accuracy.

[0082] Innovation: The third-generation Siemens dual-source CT is used for large-pitch MPI scanning, which covers a wide range and greatly reduces the radiation dose. In addition, a one-stop CCTA combined with MIP scanning is used to obtain CCTA and perfusion images at the same time, reducing the amount of contrast agents used by patients.

[0083] Analysis of technology, economic benefits and market risks

[0084] 1. Technical and economic benefit analysis

[0085] The time resolution of coronary MPI examination is high, and dynamic enhanced scanning can quantitatively evaluate myocardial blood flow, which is conducive to the evaluation of coronary vessels and myocardial vascular microcirculation changes. Siemens' third-generation dual-source CT can achieve one-stop load dynamic CT myocardial perfusion imaging, coronary CTA analysis, and whole-heart perfusion scanning. The information obtained is more comprehensive, and then a complete evaluation of the cardiac blood flow process is made, which is more advantageous. In the past, the commonly used imaging examination methods for coronary microcirculation included single-photon emission computerized tomography and magnetic resonance myocardial perfusion. The former single-photon emission computerized tomography cannot show subendocardial myocardial ischemia or infarction, and the false negative results of patients with three-vessel balanced ischemic areas are high; the latter takes a long time to examine, is expensive, and is not suitable for patients with pacemakers and metal devices, and has a limited scope of application.

[0086] 2. Analysis of the prospects for promotion and application

[0087] In recent years, with the change of people's lifestyle, the incidence and mortality of coronary heart disease in my country have continued to rise. The incidence of coronary heart disease is getting higher and higher, and cardiovascular disease deaths are also the leading cause of death among urban and rural residents, becoming a major public health problem.

[0088] Therefore, early diagnosis and reasonable prevention and treatment are very important. Stress dynamic CT myocardial perfusion imaging can effectively evaluate the distribution of myocardial blood perfusion, quantitatively evaluate coronary microcirculation disorders, improve the detection rate of myocardial ischemia, and provide a basis for early clinical diagnosis and treatment. In addition, the one-stop CT scan of MPI combined with CCTA can achieve the complementary advantages of the two examinations and complete the complete evaluation of coronary artery lesions from morphology to function. Stress dynamic CT myocardial perfusion imaging (MPI) is a non-invasive examination with fast examination, low cost, few restrictions on the scope of applicability, and broad application prospects.

[0089] 3. Project implementation risk analysis

[0090] During the examination, 40-100 ml of iodinated contrast agent needs to be quickly injected. In some elderly people, unexpected situations such as blood vessel rupture and contrast agent extravasation may occur. Some patients with highly sensitive constitutions may also be allergic to contrast agents. Therefore, a multi-faceted assessment is carried out before the examination to strictly screen out patients who may be at risk.

[0091] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A technique for detecting coronary microcirculation disturbance in patients without occlusive coronary artery disease, characterized in that: The following steps are involved: Step S1: Scanning the patient using a Siemens third-generation dual-source CT scanner, which has a large pitch scanning mode and can perform one-stop CCTA (coronary CT angiography) combined with stress dynamic CT myocardial perfusion imaging (MPI); Step S2: Before scanning, the ATP (adenosine triphosphate) dose is calculated according to the patient's body weight, and ATP is continuously intravenously pumped at a dose of 0.16 mg / (kg·min) at a uniform rate, while the patient's heart rate, blood pressure and symptom changes are monitored throughout the process; Step S3: 3 to 4 minutes after the injection of ATP, 44 ml of contrast agent was injected at a rate of 5.5 ml / s, followed by 60 ml of saline at the same rate to ensure an iodine injection rate of 2.0 g / s for 8 seconds; Step S4: After the contrast agent is injected, the MPI scan is started 5 seconds later. The scanning range covers the entire left ventricle. The cradle bed mode is used for continuous dynamic scanning. The end-systolic phase (250ms after the R wave) is completely collected once every 2 cardiac cycles. 1 to 2 minutes before the scan, the patient sprays 0.1 mg of nitroglycerin sublingually. Step S5: At the same time, CCTA scanning is performed, with the scanning range from 1 cm below the tracheal bifurcation to the diaphragmatic surface of the heart, using a prospective large pitch (Turbo Flash) scanning mode, with tube voltage automatically selected, to complete the whole heart image acquisition within a single cardiac cycle; Step S6: reconstruct the image using the advanced simulation iterative reconstruction (ADMIRE) technique to obtain the MPI image and CCTA image; Step S7: By measuring parameters such as myocardial blood flow (MBF), myocardial blood volume (MBV), time to peak pressure (TTP), and coronary flow reserve (CFR), the myocardial perfusion conditions of angina pectoris patients and healthy volunteers are compared and analyzed to objectively evaluate the changes in the myocardial ischemic area and quantitatively assess the degree and scope of microcirculatory disorders.

2. The technique for detecting coronary microcirculation disturbance in patients without occlusive coronary artery disease according to claim 1, characterized in that: The CT detector collimation of the Siemens third-generation dual-source CT scanner is 96×2×0.6mm, the MPI technology adopts the cradle bed mode and z-axis flying focus technology, the detector z-axis coverage width is 10.5cm, the gantry rotation speed is 250ms / turn, and the single-sector time resolution is 66ms.

3. The technique for detecting coronary microcirculation disturbance in patients without occlusive coronary artery disease according to claim 1, characterized in that: The MPI and CCTA scans both used automatic tube current adjustment technology (CAREDose4D, Siemens) to optimize the radiation dose.

4. The technique for detecting coronary microcirculation disturbance in patients without occlusive coronary artery disease according to claim 1, characterized in that: The Kernel value of the MPI image reconstruction is Qr36, the layer thickness is 3 mm, and the layer spacing is 2 mm; the Kernel value of the CCTA image reconstruction is Bv36, the layer thickness is 0.75 mm, and the layer spacing is 0.5 mm.

5. The technique for detecting coronary microcirculation disturbance in patients without occlusive coronary artery disease according to claim 1, characterized in that: The method is suitable for the evaluation of coronary microcirculatory disorders in patients with angina pectoris without occlusive coronary artery disease, and provides an objective basis for early clinical intervention and rehabilitation by comparative analysis with normal healthy people through load dynamic myocardial perfusion imaging.

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