BACKGROUND: Fractal dimensions always involve some averaging with respectto the given geometrical object. The classical geometrical description includes overly detailed geometricalinformation, rendering the precise formulation of equations ineffective. The problems associated withthe functionality and growth of biological systems according to their observed geometrical shape requirea specific approach. MATERIAL/METHODS: The material consists of 50 brains, 4th to 8th month of fetallife, length C.-R. 83-220 mm. The material was examined using the Pickworth method, computer image analysis(Imtronic, Scion for Windows 1998, and Elf v. 4.2), and fractal analysis. Various transformations wereapplied: numeric filters, statistical filters, binary geometrical transformations, arithmetical operations.Fractal analysis employs the 'box-counting' fractal dimension. RESULTS: The cortex vein net maintainsthe fetal character, with a large number of anastomoses, also present in adults. The size of cortex branchesamounts to 100-200 microm. The reduction of some of the anastomoses during the early stages of evolutioncomes from an increase in the vessels' caliber. During the 4th month, the fractal dimension is 1.26,increasing to 1.53 at month 5. Rapid growth of the fractal dimension has been observed until the 6thand 7th months. This means an increased complexity level and feed volume in the brain. CONCLUSIONS: Fractalsconstitute a promising and effective tool to estimate the structures of brain vessels. The fractal dimensionvaries during the fetal period. This shows the close correspondence between the structure and functionality.

Keywords: Algorithms, Cerebral Cortex, Fractals, Image Processing, Computer-Assisted, Software