"type I: (most common) both aorta and main pulmonary artery arise from a common trunk"
"type II: pulmonary arteries arise separately from the posterior aspect of trunk, close to each other just above the truncal valve (negligible main pulmonary artery segment)"
"type III: (least common) pulmonary arteries arise independently from either side of the trunk"
"type IV: neither pulmonary arterial branch arising from the common trunk (pseudotruncus), considered a form of pulmonary atresia with a VSD"
"type A1: identical to the type I of Collett and Edwards"
"type A2: separate origins of the branch pulmonary arteries from the common trunk"
"type A3: origin of one branch pulmonary artery (usually the right) from the common trunk, with other lung supplied either by collaterals or a pulmonary artery arising from the aortic arch"
"type A4: presence of an associated interrupted aortic arch"
"Collett and Edwards system"
"Van Praagh system"
"Allows direct display of anomalous anatomy. SSFP cine sequences can offer an additional functional assessment."
Expected headings
"Classifications"
"Collett and Edwards system"
"Van Praagh system"
"Associations"
"There is a lack of normal separation of the embryological truncus arteriosus into a separate aorta and pulmonary trunk. This results in a single arterial vessel that originates from the heart that supplies the systemic, pulmonary, and coronary circulations. It may also result in a common truncal valve, which can contain 2 to 4 cusps."