After the blood flow of the main blood vessel (artery or vein) in a certain part of the body is blocked, the blood vessels of the original anastomotic branch of the part expand and form bypasses, so that the blood passes through these bypasses in a roundabout way and restores the circulation, this circulatory pathway is called “collateral circulation”, also called “compensatory circulation This circulatory pathway is called “collateral circulation”, also known as “compensatory circulation”. Insufficient development of the collateral circulation means that these bypasses are not sufficiently developed, which still affects the circulation and can cause various cardiovascular diseases. What causes underdeveloped collateral circulation? There are not enough anastomotic branches between blood vessels; obstruction of blood vessels occurs so fast that collateral circulation often cannot be established sufficiently in time; and anastomotic branch vessels are not normal. There are mainly coronary artery collateral circulation, portal vein collateral circulation, cerebral artery collateral circulation and aortic collateral circulation, which should be distinguished from each other. If the collateral circulation is not developed adequately, it can cause related diseases. Chest X-rays are the most valuable routine imaging method, providing important indications and reflecting coexisting pulmonary lesions. The typical presentation is a small arterial vascular shadow on the affected side. Echocardiography can clarify the presence of other congenital cardiovascular malformations and can also determine the presence of pulmonary hypertension. Enhanced CT mediastinal windows show a direct sign of blindness at the beginning or proximal end of the artery on the side of the defect, with a regular wall and smooth dissection, and no distal shadowing or continuation of the vessel. MRI can show the artery more clearly. It has also made great progress in the diagnosis of cardiovascular malformations and has more non-invasive features than cardiac catheterization. The main types of collateral circulation are the coronary artery, the portal vein, the cerebral artery, and the aorta, which should be identified. If the collateral circulation is not adequately developed, it can cause related diseases.