Fig. 2

The fractal (i.e. non-integer) dimension is a real number that can be attributed to every natural object. The topological dimension of an object is indicated with the symbol Dγ, whereas the fractional dimension simply with D. For all Euclidean figures, Dγ and D are coincident, i.e., Dγ = D (a). This equality is not valid for the natural, including biological, objects. Natural objects can be roughly represented by Euclidean shapes (i.e., a tree resembles a cylinder, the sun is similar to a sphere, a mountain can be interpreted as a cone), but in reality, these shapes are not Euclidean figures. As suggested by Benoit Mandelbrot, it is possible to determine the Hausdorff–Besicovitch dimension or FD, of irregularly shaped objects through the covering procedure of the topological space of the object being measured. The software automatically estimates the 2D-fractal dimension of Sirius red stained pancreatic ECM (b, c). The more D tends to 2 the more the analyzed conformation tends to fill a 2D space and the greater it’s the geometrical complexity. Pancreatic desmoplasia consists of a set of irregularly shaped “collagen islets” (d)