  In X-ray imaging, photons are transmitted through and absorbed by the
subject, but are also scattered in significant quantities. Previous attempts to
use scattered photons for biological imaging used pencil or fan beam
illumination. Here we present 3D X-ray Scatter Tomography using full-field
illumination. Synchrotron imaging experiments were performed of a phantom and
the chest of a juvenile rat. Transmitted and scattered photons were
simultaneously imaged with separate cameras; a scientific camera directly
downstream of the sample stage, and a pixelated detector with a pinhole imaging
system placed at 45${}^\circ$ to the beam axis. We obtained scatter tomogram
feature fidelity sufficient for segmentation of the lung and major airways in
the rat. The image contrast in scatter tomogram slices approached that of
transmission imaging, indicating robustness to the amount of multiple
scattering present in our case. This opens the possibility of augmenting
full-field 2D imaging systems with additional scatter detectors to obtain
complementary modes or to improve the fidelity of existing images without
additional dose, potentially leading to single-shot or reduced-angle tomography
or overall dose reduction for live animal studies.
