Fully anisotropic morlet transform for the study of the trabecular bone texture variations.

This paper presents a new method for the characterization of trabecular bone texture variations for early detection of osteoporosis. It relies on the study of texture variations in the complex-anisotropic domain associated with the Fully Anisotropic Morlet transform (FAM). Unlike conventional oriented wavelet-based schemes, this not only allows analyzing the texture over a wider range of scales and directions but also enables to consider the texture anisotropy. More specifically, we propose a new directional-signature which is a function of the orientation and relative magnitudes to characterize the radiographic bone anisotropy. The investigation of the inter-scale dependencies within an complex- anisotropic neighboring of FAM coefficients allows to capture separately the local-statistical properties of each directional sub-band, which is of great interest for the analysis of the trabecular bone texture exhibiting complex-irregular behavior. Results show that the proposed feature vector enables to discriminate two populations composed of Osteoporotic Patients (OP) and Control Cases (CC) with an Area Under Curve (AUC) rate of 91.28%.