Early results for equivalent wavefield transform as a direct solution to the inverse problem for active infrared thermography and potential for perfusion information to differentiate healthy versus cancerous breast tissue

The purpose of this work is to introduce a new analytical inversion method for three-dimensional (3D) sub-surface imaging beneath the skin from time sequenced infrared (IR) thermography images. The work was motivated by advances in transient thermal nondestructive evaluation methods. Using relationships between wave propagation and thermal diffusive propagation, transformation from diffusive propagation into an equivalent wave field is performed. This transformation results in well-defined reflections with time delay proportional to the distance. We apply the algorithm to a dynamic thermogram of the breasts obtained from the Brazilian breast thermal imaging set. Inversion of the raw data reveals intensities that correspond to heat conduction. Equivalent wave field transform (EWFT) serves as a computationally efficient method of extracting depth resolved anatomical and physiological information from skin surface thermogram data.