Open or closed: Changes in ductus arteriosus flow patterns at birth using 4D flow MRI in newborn piglets

Area of Science:

• Cardiovascular Physiology
• Neonatal Physiology
• Medical Imaging

Background:

• The ductus arteriosus (DA) is a fetal blood vessel that normally closes shortly after birth.
• Understanding the dynamics of DA closure is crucial for neonatal health.
• Previous studies lacked comprehensive measurements of heart output during this transition.

Purpose of the Study:

• To combine 4D flow MRI and T2 relaxometry to precisely measure and visualize right and left heart output during DA transition.
• To assess the relationship between DA status and blood flow distribution in newborn piglets.

Main Methods:

• Utilized 4D flow MRI for dynamic volumetric blood flow measurements.
• Employed T2 relaxometry for oxygen delivery quantification.
• Studied surgically instrumented newborn piglets across four age groups.

Main Results:

• Vessel diameters and blood flow normalized to body weight increased with age.
• Reversed DA blood flow was associated with lower common carotid artery blood flow.
• Decreasing net DA flow correlated with decreased common carotid artery flow and increased pulmonary artery flow.
• Bidirectional DA flow altered oxygen saturation between the ascending and descending aorta.

Conclusions:

• The study provides novel, explicit measurements of cardiovascular changes during DA transition.
• Findings highlight the impact of DA status on cerebral and pulmonary blood flow.
• These advanced imaging techniques show promise for studying neonatal circulatory adaptations and testing interventions.