  We present numerical reconstructions of anisotropic conductivity tensors in
three dimensions, from knowledge of a finite family of power density
functionals. Such a problem arises in the coupled-physics imaging modality
Ultrasound Modulated Electrical Impedance Tomography for instance. We improve
on the algorithms previously derived in [Bal et al, Inverse Probl Imaging
(2013), pp.353-375, Monard and Bal, Comm. PDE (2013), pp.1183-1207] for both
isotropic and anisotropic cases, and we address the well-known issue of
vanishing determinants in particular. The algorithm is implemented and we
provide numerical results that illustrate the improvements.
