The nondestructive evaluation (NDE) of materials often involves the solution of an inverse problem. It is shown that image reconstruction techniques lead to the direct solution of the 3-D inverse problem when radiographic measurements are made. In particular, it is suggested that the convolve-and-backproject solution to the 3-D divergent ray geometry problem should be useful for NDE. There is also a discussion of the accept-reject criteria appropriate for various classes of defects.