blood to the pulmonary arteries flowing through the persistently
patent arterial duct. In the other half, the pulmonary
arterial supply is multifocal. In these patients, if the
pulmonary arteries are confluent or continuous, the
blood supply will likely originate only from multiple
aorto-pulmonary collateral arteries (Figure 5). If the pulmonary
arteries are discontinous or absent, the blood supply
to the lungs will originate from multiple collateral
arteries, or from a combination of collateral arteries and
an arterial duct. It is a general rule that a pulmonary segment
will not be supplied by both an arterial duct and a
collateral artery [6]. In cases of complex supply of blood
to the lungs, it is necessary to determine the proportion of
pulmonary parenchyma supplied by the intrapericardial
pulmonary arteries as opposed to those parts supplied
exclusively by the collateral arteries [6,11,12].