1. A system for non-intrusive analysis of internal features of an object, the system comprising: scanning means for continuous scanning of an object as the object moves in an axial direction relative to the scanning means, the continuous scanning providing spiral scan data according to the internal features of the object, the object and the scanning means further moving in a rotational relationship with respect to one another; and construction means for processing the spiral scan data to generate one or more density distributions of one or more cross-section of the object, wherein in generating a density distribution of a cross-section of the object, the construction means applies a planar reconstruction technique to the spiral scan data.