The present work describes progress on developing imaging algorithms that use fast neutron signatures acquired using the associated-particle imaging (API) method. The present work complements ongoing work to develop neutron source and detector hardware to enable field inspection by investigating algorithms that can discriminate among critical materials or extract 3D geometrical information from single-sided or transmission measurements. The present work has three focus areas:1. Iterative reconstruction of inelastic gamma-ray emissions to perform 3D time-of-flight (TOF) imaging in a single view in either transmission or backscatter configurations. Iterative reconstruction enables better image resolution than the inherent TOF resolution.2. Decomposition of registered neutron and x-ray radiographs into an assumed material list for each pixel in the image.3. Material identification using full spectral analysis that includes the emergent neutron and gamma-ray energies, times, and angles.Progress for each approach is summarized for FY 2022.