Coronary angiography is the core technology in the diagnosis and treatment of coronary heart disease. The left main coronary artery (LMCA), which supplies most of the left ventricular myocardium, is the key segment of the coronary network, but because of its special anatomical characteristics, it limits the value of coronary angiography in the diagnosis. Intravascular ultrasound, as an invasive tomographic technique, has been widely used in clinic to assist coronary angiography, and its value in diagnosis and treatment of left main artery disease has been recognized by most studies.

In view of the challenges and opportunities presented in the new century and after rational deliberations on five occasions, the completely new model of "hi tech+humanistic solicitude=the green hospital" was put forward and the overall framework of "one line of thought", "two cornerstones", and "three goals" was carefully formulated. In the meantime, all staff members of the hospital were called on to be involved in the "six major activities". As a result, great changes have taken place in the appearance and development of the hospital. It has been proved through practice that "the green hospital" is a successful model conforming to the trends of the times.