The formation of sulcal and gyral patterns in the human brain is genetically programmed. It can be altered by environmental influences such as hypoxia-ischemia, nutrition and drug exposure. No current imaging modality can quantitatively monitor the development of the cerebral surface and underlying cortical gray matter (GM). The aims of this study were to quantitate this development in the living infant with advanced MRI techniques.

Design/Methods: 6 preterm infants (GA:28-29) and 6 fullterm infants (GA:38-40) were studied with MRI. Post-processing of 3D-MRI data included automated segmentation of brain tissue classes, masking of cerebral hemispheres, measurement of GM volume and measurement of cortical surface with a triangulation algorithm. Surface change due to increased gyration was expressed as the ratio between the measured surface (Sg) and the surface after smoothing (Ss) by a dilation and erosion step.

Results: Table1 shows the striking increase of cortical GM from preterm to term. Surface (Sg) also increases markedly. The increase in Sg/Ss-ratio increase reflects the surface increase due to increased gyration.

Table 1
Full size table

Conclusion: We document by advanced MRI, for the first time, striking quantitative changes in the development of cortical gyration and cortical GM in the living infant. Study of infants subjected to various insults with this approach should provide major insight into effects on these critical developmental events.