4D Cardiac MRI Flow in Neonates - Cardiac Output in full-term healthy neonates

Area of Science:

• Cardiovascular Imaging
• Pediatric Cardiology
• Medical Physics

Background:

• Accurate assessment of cardiac flow and volumes is crucial for managing pediatric heart disease.
• Cardiovascular magnetic resonance (CMR) offers comprehensive evaluation but is challenging in neonates, often requiring sedation or contrast agents.
• Free-breathing four-dimensional (4D) flow CMR simplifies acquisition and avoids anesthesia, but its use in unsedated neonates needs validation.

Purpose of the Study:

• To evaluate the feasibility, accuracy, and interobserver reproducibility of free-breathing, non-contrast 4D flow CMR in healthy, unsedated neonates.
• To establish normative data for cardiac flow parameters in the neonatal period.
• To characterize the postnatal development of cardiac flow dynamics.

Main Methods:

• One hundred healthy term neonates underwent free-breathing, ECG-gated, axial 4D flow CMR without sedation.
• Cardiac output (CO), cardiac index (CI), pulmonary blood flow (Qp), systemic blood flow (Qs), and Qp/Qs were quantified.
• Interobserver reproducibility was assessed by three independent observers.

Main Results:

• Free-breathing 4D flow CMR was feasible in 70% of neonates with a mean scan time of 9.3 minutes.
• Neonatal cardiac index increased significantly during the first month of life, primarily due to rising stroke volume.
• Excellent interobserver reproducibility was observed (ICC > 0.9), with good agreement between 4D flow and volumetric measurements.

Conclusions:

• Free-breathing, non-contrast 4D flow CMR is a feasible and reliable technique for assessing neonatal cardiac function.
• The study provides valuable normative data on postnatal cardiac flow development.
• This non-invasive method has significant potential for clinical translation in pediatric cardiology.