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 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 histologically confirmed breast carcinoma obtained from the Brazilian breast thermal imaging set. Inversion of the raw data reveals intensities that correspond to heat conduction, most notable is presence of hyperintense, aberrant vascularization in the diseased breast in comparison with the non-diseased breast. Equivalent wave field transform (EWFT) serves as a computationally efficient method of extracting depth resolved anatomical and physiological information from skin surface thermogram data for research purposes.