Standard method for ultrasound imaging of coronary artery in children

The Child Coronary Arterial Diameter Reference Study Group of the Japan Kawasaki Disease Society recommends ultrasound imaging as the standard method for measuring the diameter of the coronary artery in children. The patient is examined in a supine or right decubitus position by using a sector probe (≥5 MHz). The coronary arterial diameter measured at the minimum gain setting is the distance between the internal echo edge and the internal echo edge. The diameter is measured during the early diastolic phase at the end of the T wave. The left main coronary artery and the proximal right coronary artery are approached from the precordial short axis at the level of the aortic valve. The proximal and mid‐right coronary arteries are observed on the atrioventricular groove, anterior to the tricuspid valve ring. The right coronary artery of the acute margin of the heart runs along the right side of the tricuspid valve ring. The distal right coronary artery is observed on the posterior atrioventricular groove, and the posterior descending branch of the right coronary artery is observed on the posterior interventricular groove. The right coronary artery is also well observed from the right sternal border in the right decubitus position. Proximal and mid‐anterior descending arteries are observed on the anterior interventricular groove. The proximal left circumflex coronary artery is observed in the atrioventricular groove, anterior to the mitral valve ring.