Catheterization can be a method of diagnosis or a treatment. The most important reason for using angiography is to check coronary arteries and heart anatomy. In this way, the doctor specializing in echocardiography of the heart can diagnose the disease by taking pictures of the blood vessels, and the location and size of the blocked vessels can be determined. In order to use this method for treatment, drugs enter the body in this way. Sometimes the doctor uses angiography in order to choose the best treatment method so that the blood flow in the heart is done well. These catheters are long enough and their end tip advances into the heart or coronary or pulmonary arteries and is placed there. These catheters usually have tapered end tips and curved proximal ends that are connected to connecting devices or hubs.