Fast onsite electromagnetic imaging method for medical applications

Abstract

Born's iterative technique is widely used in inverse scattering problems, including electromagnetic medical imaging. The method, nevertheless, suffers from some limitations associated with the applicability range, and accuracy. In this work, it will be shown that replacing the popularly-used electric wave equation by its magnetic counterpart in inverse scattering formulation, leads us to significantly improve the above limitations. To this end, and using the magnetic wave equation, the field-dependent contrast source of the imaged object, is divided into two spatial types of sources: The known average contrast source, and the small unknown fluctuation contrast source. Then, considering the known average contrast source as the background domain, the Born's method is only supposed to detect the small fluctuations, which enhances its applicability range to high contrast dielectrics. Moreover, the very nature of the magnetic wave equation adds another integral term to the Born's iterative method, containing an operator called the fluctuation operator, which improves the accuracy of the method in detecting the biological abnormalities. The validity of the proposed technique is successfully verified via simulations performed on a realistic head model. As the Born's method is naturally time-efficient, the proposed method can be considered as a reliable tool for 2D medical imaging in emergency scenarios.