[The fractal dimension as an imaging parameter in CT scans of patients with anorexia nervosa before and after therapy].

Brain development is a self-organizing process and hence the brain structures correspond to a highly recursive system consisting of a multitude of parts. Quantitative analysis of recursive, self-similar structures is possible in CT scans as what is termed synergistic diagnostic using the fractal dimension. In 10 patients with anorexia nervosa (ICD-10, F50.0) we determined the fractal dimension of the cerebral cortex contour in a CT image using the "boxcounting method" after filtering of the data and separation with a defined cut-off. There was a significant difference between the results from CTs obtained before and after therapy. There was a high correlation between the fractal dimension and body weight, brain volume and sulcal cerebrospinal fluid volume, but only a low correlation with ventricular volume. The findings suggest that the qualification of the fractal dimension may be useful as one of postprocessing methods on CT scans. Further studies will be necessary to assess its importance for diagnosis.