DSA examination is digital silhouette angiography, which is a vascular imaging technique that eliminates skeletal and soft tissue shadow images by injecting contrast into blood vessels and digitally processing the image information using a computer. DSA is mainly used in the following clinical applications: 1. Diagnosis of vascular diseases, such as vascular rupture, aneurysm, arteriovenous malformation, arteriovenous fistula, and vascular stenosis occlusive diseases. 2. Diagnosis and localization of small blood-rich tumors, such as insulinoma, parathyroid adenoma, etc. 3. Preoperative evaluation of vascular anatomy, local tumor resection, organ transplantation, etc. In addition, there are also percutaneous endovascular treatments performed, such as transcatheter drug perfusion, balloon angioplasty, stent placement, thrombolysis, etc. It is still widely used in clinical practice.