[Table/Fig-16]:

Truncus arteriosus.

Subtypes: Collett and Edwards classification [18]	Type I = pulmonary trunk arises from proximal truncus Type II and III= no pulmonary trunk; branch PA arise from posterior and lateral mid-segments of truncus Type IV=pulmonary circulation dependent on MAPCAs.
Incidence	1% of CHD. 1 in 11,000 live births(10–5)
Association [13]	Right aortic arch, interrupted aortic arch, coarctation, PDA Coronary artery anomalies(stenotic coronary ostia, abnormal branching and course) Unilateral absence of pulmonary artery
Syndromes	DiGeorge syndrome Pierre Robin syndrome
Imaging features Plain	Moderate cardiomegaly with narrow base	High cephalic origin of PA	Right aortic arch	Depressed diaphragm	Thymic atrophy
Imaging features specific	Echo large truncus, large VSD and a large echogenic truncal valve with fibrous continuity with anterior mitral leaflet MRI -similar findings
Management	Primary repair: done in first week of life; consists of VSD closure and placement of valve conduit between RV and PA (Rastelli procedure)