[New horizons in medicine. Fractals]

In these last few years, a vertiginous growth in the application of informatics in the field of science has generated a new branch of geometry: the geometry of irregularity whose paradigmatical expression is fractals. We can identify in the fractal an object of complex structure which, when gradually enlarged, shows up details which repeat themselves as the scale of enlargement is progressively run through. It is possible, therefore, by using fractals to study and quantify in a much more concise way and much less approximatively those structures which were until recently described as granulous, tentacular, ramified, etc. Fractals bridge the gap between mathematics and visual art and allow us to explore the rapport between determinism and apparent chaos in the study of non-linear biological systems. Fractal dimension is an intermediary one between linear and surface dimensions. The applications of fractals images in the study of certain problematics which concern the cardiovascular system are referred to synthetically; particularly those concerning the sectorial differences of myocardial blood flow and the branches of small coronary vessels, both in physiological and pathological conditions. Fractal images permit us to analyse the regional flow of the pulmonary parenchyma, and to quantify pulmonary damage from thromboembolism. Other applications of fractal studies regard the digestive system, the nervous system and mammary pathology. In specialistic fields, fractals have been studied in both ophthalmology and odontology, and also in biochemistry to study protein surfaces and fluids turbulence.