Abstract
A 14-year-old boy developed coronary aneurysms during the course of Kawasaki disease. The vessel wall morphology of the coronary arteries was assessed by intravascular ultrasound imaging (IVUS). There was intimal thickening proximal to, within, and distal to a large coronary aneurysm in the left anterior descending coronary artery only 18 months after the acute onset of Kawasaki disease. Intimal thickening without calcification is a new IVUS finding within a persistent coronary aneurysm. It may indicate that the healing process, via cell proliferation is continuing, with the risk of causing a stenosis.