Microarchitecture of the hearts in term and former-preterm lambs using diffusion tensor imaging

Area of Science:

• Biomedical Engineering
• Cardiovascular Imaging
• Developmental Biology

Background:

• Diffusion Tensor Imaging (DTI) is an advanced MRI technique.
• DTI maps cardiomyocyte tracts and estimates orientation within the heart.
• Water diffusion in myocardium is anisotropic, influenced by cell membranes and extracellular matrix.

Purpose of the Study:

• To compare cardiac microarchitecture and cardiomyocyte organization in preterm versus term lambs.
• To assess the feasibility of retrospective DTI scanning on archived fixed hearts.
• To investigate potential microstructural differences in the left ventricle (LV) of preterm neonates.

Main Methods:

• Diffusion Tensor Imaging (DTI) applied to archived fixed left ventricles.
• Comparison between lambs born preterm (n=5) and at term (n=7).
• Postnatal age equivalent to 6 years in children.

Main Results:

• Feasibility of retrospective DTI scanning on fixed hearts was supported.
• Poor scan quality (e.g., ghosting artifacts) led to exclusions.
• Viable DTI scans (n=3/group) indicated altered extracellular compartment and immature microstructural phenotype in preterm lambs' LV.

Conclusions:

• DTI can potentially detect abnormal microstructural changes in fixed hearts of former preterm neonates.
• An immature microstructural phenotype is suggested early in postnatal life for preterm lambs.
• Further investigation is needed to optimize DTI scan quality for clinical application.