In this study, tomograms of bituminous mixtures with a photon energy (E) of 120 kV are taken with a multidetector X-ray scanner. These tomograms are cross-sectional images of the internal structure of specimens in a cutting plane surface. The purpose of taking these tomograms was to find out the main factor/factors causing different fatigue lives for replicated specimens using images of the internal structure of specimens. After taking the tomograms, the fatigue tests were carried out using repeated-loading indirect tensile test equipment. In addition to conventional fatigue model parameters, new parameters, which are acquired from the cross-sectional surface tomograms, are taken into consideration to be able to explain the variations in the fatigue lives of similar specimens. These new models help explain the variations in fatigue lives of similar specimens tested under identical conditions. Hence, tomograms will help us define the fatigue lives of specimens in a nondestructive way.