Fractal dimension and image statistics of anal intraepithelial neoplasia

It is well known that human papillomaviruses (HPV) induce a variety of tumorous lesions of the skin. HPV-subtypes also cause premalignant lesions which are termed anal intraepithelial neoplasia (AIN). The clinical classification of AIN is of growing interest in clinical practice, due to increasing HPV infection rates throughout human population. The common classification approach is based on subjective inspections of histological slices of anal tissues with all the drawbacks of depending on the status and individual variances of the trained pathologists.Therefore, a nonlinear quantitative classification method including the calculation of the fractal dimension and first order as well as second order image statistical parameters was developed. The absolute values of these quantitative parameters reflected the distinct grades of AIN very well. The quantitative approach has the potential to decrease classification errors significantly and it could be used as a widely applied screening technique.

Research Highlights
► Human papillomaviruses cause anal intraepithelial neoplasia (AIN).
► Digital image processing was carried out to classify the grades of AIN quantitatively.
► The fractal dimension as well as grey value statistics was calculated.
► Higher grades of AIN yielded higher values of the fractal dimension.
► An automatic detection system is feasible.