Neonatal cardiac MRI using prolonged balanced SSFP imaging at 3T with active frequency stabilization

Area of Science:

• Medical Imaging
• Cardiovascular Imaging
• Neonatal Medicine

Background:

• Neonatal cardiac MRI presents challenges due to patient size, heart rate, and lack of breath-holding.
• Balanced Steady-State Free Precession (SSFP) offers high SNR but is susceptible to off-resonance banding artifacts, especially in blood pools.

Purpose of the Study:

• To evaluate active frequency stabilization and image-based shimming for prolonged SSFP cardiac MRI in preterm infants.
• To assess the effectiveness of this method in mitigating banding artifacts and improving image quality.

Main Methods:

• 2D multislice SSFP cine acquisitions were performed on 18 preterm infants.
• Active frequency stabilization and image-based shimming were employed to maintain image quality over 10-minute scans.
• Functional measures were validated against phase-contrast flow assessment.

Main Results:

• Significant resonant frequency drifts (165 ± 23Hz) were observed without stabilization.
• Banding artifact-free imaging was achieved in 16 out of 18 subjects using the stabilization method.
• Cardiac output measurements showed a mean difference of 9.0 ± 8.5% compared to phase-contrast flow data.

Conclusions:

• Active frequency stabilization enables prolonged SSFP acquisitions for neonatal cardiac imaging at 3T.
• This technique effectively reduces banding artifacts, improving image quality and functional assessment in neonates.
• The findings have potential implications for other SSFP applications requiring prolonged imaging.