Building an image-based system to automatically score psoriasis

Abstract

Nowadays the medical tracking of dermatological diseases is imprecise. The main reason is the lack of suitable objective methods to evaluate the lesion. The severity of the disease is scored by doctors just through their visual examination. In this work, a system to take accurate images of dermatological lesions has been developed. Mathematical methods can be applied to these images to obtain values that summarize the lesion and help to track its evolution. The system is composed of two elements. A precise image acquisition equipment and a statistical procedure to extract the lesions from the images. The system is tested on patients with the dermatological disease psoriasis. Temporal series of images are taken for each patient and the lesions are automatically extracted. Results indicate that to the images obtained are a good source for obtaining derived variables to track the lesion. Keywords: image acquisition, camera calibration, mixture distribution, discriminant analysis, E-M algorithm, psoriasis. © Springer-Verlag 2003.