A Biometric Identification System based on Thyroid Tissue Echo-morphology

This paper proposes a biometric system based on features extracted from the thyroid tissue accessed through 2D ultrasound. Tissue echo-morphology, which accounts for the intensity (echogenicity), texture and structure has started to be used as a relevant parameter in a clinical setting. In this paper, features related to texture, morphology and tissue reflectivity are extracted from the ultrasound images and the most discriminant ones are selected as an input for a prototype biometric identification system. Several classifiers were tested, with the best results (90% identification rate) being achieved with the maximum a posteriori classifier. Another classifier which only takes into account the reflectivity parameter achieved a reasonable identification rate of 70%. This suggests that the acoustic impedance (reflectivity) of the tissue is a good parameter to discriminate between individuals. This paper shows the effectiveness of the proposed classification, which can be used not only as a new biometric modality but also as a diagnostic tool.