A variety of special tests can be used to diagnose aortic coarctation. For example, an enlarged aortic bulb and widened mediastinum can be seen on a chest radiograph, but a chest radiograph cannot be used as a confirmatory diagnostic tool for entrapment. Enhanced CT is commonly used to diagnose aortic coarctation. It has the characteristics of safety, simplicity, accuracy and economy. Therefore, enhanced CT is of great value in both the diagnosis and preoperative evaluation of aortic coarctation. Magnetic resonance angiography (MRA) is also a good method to diagnose aortic coarctation, but MRA images are slightly blurred, especially in measuring the internal diameter of blood vessels, which is not accurate enough. Transesophageal ultrasound (TEE) is a safe, noninvasive, sensitive and specific method for the diagnosis of aortic coarctation, and it can make a diagnosis of aortic coarctation very accurately and quickly, with the disadvantage that the operation cannot be successfully completed in patients with unstable conditions in the emergency department, and there are limitations in the observation of the arch and its branch vessels due to the interference of the trachea. Also TEE cannot observe abdominal aortic entrapment and fissures. Digital subtraction angiography (DSA) is an effective means of diagnosing aortic coarctation, but because it is invasive and expensive, DSA techniques are more often used in endoluminal treatment techniques for aortic coarctation.