Whether a stent can be placed in a thin coronary vessel depends on the degree of stenosis, which can be evaluated by intravascular ultrasound to determine whether a stent can be implanted. It is important to be cautious about placing stents in thin coronary arteries, as thin vessels increase the risk of in-stent restenosis. Patients with thin coronary arteries can undergo an intravascular ultrasound examination to find out the diameter of the blood vessel. Patients who meet the criteria for stent implantation can have a stent implanted; patients with too thin a blood vessel should not have a stent implanted, but can have their coronary arteries dilated by medication with a balloon therapy. Patients with coronary artery disease should routinely undergo coronary angiography to understand the severity of coronary artery lesions, which should be evaluated by a professional physician to determine whether interventional therapy can be performed.