Coronary angiography is a relatively safe and reliable invasive diagnostic technique, clinically considered the "gold standard" for diagnosing coronary heart disease. In 1989, Canadian doctor Campeau performed trans-radial angiography (TRA) for the first time percutaneous puncture of the radial artery. In 1993, Dutch doctor Keimeneij and others completed the first trans-radial coronary intervention (trans-radial intervention, TRI) . After nearly 30 years of clinical practice, the radial artery approach has become the first choice for coronary intervention and treatment. Compared with the femoral artery approach, the radial artery approach has the advantages of fewer traumas, less risk of bleeding, shorter hospital stay, and patients' early mobility. However, there are also few disadvantages of the radial access, such as small inner diameter, repeated puncture prone to spasm, limiting the implantation of larger sheaths to treat complex coronary artery diseases and postoperative complications such as thickening and stenosis and occlusion of the radial artery. The incidence is higher, and so on.Previous studies have found that the mismatch between the radial artery's inner diameter and the sheath's diameter is an essential factor that causes complications such as thickening, stenosis, and occlusion of the radial artery after intervention. Patients with coronary heart disease often need to repeat coronary interventional examinations and treatments. To ensure the radial artery route and avoid complications such as radial artery occlusion (RAO) after intervention for repeated use. It is worthy of attention. At present, in clinical ascending coronary angiography (CAG) or coronary interventional therapy (PCI), most of the radial artery sheath sizes are not selected according to the diameter of the patient's radial artery. The surgeon is only subjectively based on the patient's radial artery pulsation strength and coronary artery pulsation. It depends on the complexity of the pulse pathology. The incidence of radial artery occlusion reported in previous studies is 5%-38%. Most of these studies only rely on clinical forearm examination and pulse palpation without vascular ultrasound, radial angiography, and other imaging examinations to assess catheter placement. The degree of patency of the posterior radial artery has caused considerable differences in the reported incidence of radial artery occlusion. However, PCI treatment of complex lesions such as bifurcation, high calcification, severe distortion, chronic total occlusion, etc., usually requires a 7F sheath to provide better support and convenient equipment delivery. Still, the latter has the following problems: on the one hand, patients' pain, vasospasm, and other reasons can easily lead to failure of the radial artery sheath grafting; on the other hand, although the 7F sheath is used to complete PCI for complex lesions, the postoperative Radial artery occlusion is prone to occur, resulting in long-term failure to undergo re-radial artery angiography or PCI treatment.The innovation of this study lies in the use of ultrasound and radial angiography for the measurement of the inner diameter of the patient's radial artery, to examine the distribution of the inner diameter of the radial artery, and to predict the cut-off value of the radial artery inner diameter for successful sheath implantation and the inner diameter resection of the radial artery occlusion after the operation. The point value provides an evidence-based basis for selecting the sheath size of the radial artery in the future to achieve the clinical purpose of protecting the radial artery for repeated use.

Inclusion Criteria:

1. Those who are diagnosed or suspected of having coronary heart disease;
2. Patients undergoing first time selective interventional surgery via the right radial artery;
3. Those who can understand the purpose of this experiment, participate in this study voluntarily, and sign an informed consent form.

Exclusion Criteria:

1. Have a history of PCI through the right radial artery;
2. Those with deformity, trauma, or amputation of the right upper limb;
3. Those who have negative Allen's test;
4. There are other contraindications to coronary angiography surgery.

This study adopts a continuous enrollment method. It is estimated that 500 patients will be enrolled within the study period.