Three-dimensional microwave tomography: Experimental imaging of phantoms and biological objects

Microwave tomographic experiments have been performed on a three-dimensiona l (3-D) phantom and excised canine heart using a 3-D system operating at Fr equency of 2.4 GHz, A modified gradient reconstruction approach has been em ployed for the 3-D image reconstruction. To compare two-dimensional (2-D) a nd 3-D approaches, we also performed 2-D image reconstruction using an appr oach based on the Newton method. Experimental data acquired on experimental phantoms were analyzed using both 2-D and 3-D reconstruction approaches. H igh-quality images were reconstructed using the 3-D approach. The reconstru ction procedure failed when the 2-D approach was applied to reconstruct ima ges of the 3-D object. An image of the dielectrical properties of the excis ed canine heart was obtained using a 3-D reconstruction approach. Images su ccessfully revealed a complex internal structure of the heart, including bo th right-hand side and left-hand side ventricles.