Biomedical Imaging and Impressioning using Low-Frequency Electromagnetic Energy

The advent of X-Ray Computerized Tomography using Radon transforms for imaging of human bodies in the 1970s gave rise to a strong interest in imaging using microwaves. The primary thrust behind such interest lied in the non-harmful effects of low-power microwaves in comparison to potentially ionizing X-rays. The field of imaging using microwaves has traditionally evolved based on inverse scattering theories that were steeped in integral equations’ formulations of the electromagnetic radiation or acoustic problems. Inverse scattering problems were fundamentally based on reconstructing the dielectric permittivity or magnetic permittivity profile of a specific medium or object. In biomedical imaging, however, reconstructing the precise concise profile of the object (such as the human body), is not of importance but rather generating an image or an impression that indicates the presence of an anomaly such as a fracture in a bone, a blood clot, or a tumorous growth within the body. In these modalities, the primary goal is to create a contrast between the constituents of the human body. Therefore, mathematically complex ill-posed inverse scattering methods may not be most suitable or even practical for imaging or impressioning human bodies.