Back   Figure 13A-D. Right unifocalization. A. Selective injection in the right pulmonary artery via a left BT shunt demonstrates a good size branch to the right lower lobe and very small branch to the right upper lobe.    B. Selective injection in a MAPCA to the right lower lobe in the same patient. Note the presence of severe mid segment stenosis.    C. Additional MAPCA from the underside of the aortic arch to the right upper lobe with evidence of proximal stenosis.   D. Selective injection in the right pulmonary artery following unifocalization of the two right-sided MAPCA’s showing significantly improved flow to the right upper lobe, as well as increased perfusion to segments of the right lower lobe. There are no significant peripheral stenoses visible. BT = Blalock-Taussig, MAPCA = major aortopulmonary collateral artery. Back www.impaedcard.com