This paper proposes a numerical assessment of brain stroke follow-up via differential Microwave Imaging. The aim is to follow the evolution of the patient’s stroke growth and location, in order to support decisions in the clinical treatment. We present a fully 3D algorithm for Differential Microwave Imaging with arbitrary illuminations for which the vector nature of the equations is conserved, thus not limited to the simple cases of TE or TM excitations. Thanks to the effectiveness and flexibility of the adopted forward modelling tool, the approach can handle complex scenarios and large grids