A linear model for chirp-pulse microwave computerized tomography: applicability conditions

Chirp-pulse microwave computerized tomography (CP-MCT) represents an innovative medical imaging technique. One of the advantages of CP-MCT is that data reduction is based on the standard algorithm of x-ray tomography, namely filtered back-projection and therefore is very fast, even if not very accurate. For this reason we recently proposed a modification of this algorithm based on a linear model, hence on a computationally efficient approach. The method has been validated by means of real data obtained with the Niigata prototype of the CP-MCT scanner. However, the applicability of the underlying model has not yet been completely analysed. In this paper, we first investigate the assumptions leading to the linear model and then we show, by means of numerical simulations, that it can provide quantitative maps of the attenuation constant of the body in the low-contrast case.