In this work, the advantages of 3D printed anthropomorphic phantoms applied to the assessment of microwave imaging devices and the potential contribution of their numerical version for microwave imaging are examined. Three phantoms that represent main body areas are used for illustration: head, breast and thorax. The context of the analysis deals with dynamic imaging where several data sets are taken from a body at different moments and the image is reconstructed from the difference in the scattered field recorded. The work is focused on the effect of a local change of the dielectric properties on the differential field distribution and constitutes an example of what can be done with the numerical version of the 3D printed anthropomorphic phantoms.