Age-specific gray and white matter DTI atlas for human brain at 33, 36 and 39 postmenstrual weeks

Area of Science:

• Neuroscience
• Medical Imaging
• Developmental Biology

Background:

• Dramatic structural changes occur in the human brain during the 3rd trimester, crucial for neural circuit formation.
• Increased survival rates of premature infants highlight the need for specialized tools to study their developing brains.
• Significant morphological differences exist between preterm and full-term infant brains, necessitating age-specific atlases.

Purpose of the Study:

• To establish age-specific diffusion tensor imaging (DTI) templates and atlases for preterm and term-born brains at 33, 36, and 39 postmenstrual weeks (PMW).
• To provide detailed anatomical labeling of major gray matter (GM) and white matter (WM) structures within these age-specific atlases.
• To demonstrate the utility of these atlases in understanding normal brain maturation and detecting neural disorders in preterm infants.

Main Methods:

• Acquisition of high-quality DTI data from 84 healthy preterm and term-born neonates.
• Development of age-specific DTI templates, including single-subject, linearly transformed population-averaged, and nonlinearly transformed population-averaged templates.
• Comprehensive labeling of 126 major GM and WM structures within the atlases, covering cortical, subcortical, brainstem, and cerebellar regions.

Main Results:

• Established age-specific DTI templates and atlases for brains at 33, 36, and 39 PMW.
• Revealed dramatic morphological changes in neural structures like the ganglionic eminence and uncinate fasciculus between 33 and 39 PMW.
• Demonstrated reliable and reproducible automated labeling using age-matched atlases, validated by Dice ratio and L1 error metrics, outperforming manual delineation.

Conclusions:

• The developed age-specific DTI atlases accurately represent brain maturation in preterm and term infants.
• These atlases enable effective automatic delineation of microstructural changes in white matter tracts during the 3rd trimester.
• The atlases serve as a valuable tool for understanding normal brain development and identifying biomarkers for neural disorders in preterm populations.