Quantification of Ductus Arteriosus Shunt Volume in Preterm Infants using Phase Contrast CMR

Kathryn Mary Broadhouse¹, Anthony N. Price¹, Giuliana Durighel¹, David J. Cox¹, A. D. Edwards¹, J. V. Hajnal¹, Alan M. Groves¹

Persistent Patent Ductus Arteriosus (PDA) remains a common clinical presentation in preterm infants. Phase contrast MRI was used to quantify volume of ductal shunt and define the impact of PDA shunt on true systemic perfusion. Volume of left ventricular output and systemic blood flow (in the superior vena cava and descending aorta) was quantified in preterm infants. In infants with proven ductal closure, measured volume of systemic flow was closely correlated to left ventricular output. In infants with a PDA the volume of ductal shunt was variable, but accounted for up to 60% of left ventricular output. It was also demonstrated that a significant PDA determined by classical measures may not always cause systemic hypo-perfusion.