Improving Quantitative Microwave Holography Through Simultaneous Use of the Born and Rytov Approximations

Microwave near-field imaging has shown marked progress in biomedical diagnostics, including stroke detection and cancer diagnostics, though clinical devices are not yet available. The challenge of achieving high-quality image reconstruction in real time stems from the complexities of near-field scattering in the strongly heterogeneous tissue environment. Recent experiments have demonstrated the ability of quantitative microwave holography (QMH) to reconstruct the permittivity of complex tissue phantoms in real time. QMH has been applied so far in two separate versions, one based on Born’s approximation of the data equation of scattering and the other based on Rytov’s approximation. Here, we show how to reconstruct the quantitative images using both approximations simultaneously. This new reconstruction leads to images of improved resolution and quantitative accuracy compared to the two previous QMH versions. Experiments with tissue phantoms demonstrate the improvement.