Background: The effects of two lipidlowering drugs, simvastatin and fenofibrate on osteoporosis in the femurs of healthy and ovariectomized female rats were investigated quantitatively by histological images and 1H NMR relaxometry. Methodology: The intertrabecular cavities percentage was estimated from numerically cleaned histological images which initially present both the trabecular bone architecture and bone marrow filling the intertrabecular pores. The eight weeks evolution of intertrabecular cavities percentage measured from histological images of randomly selected sections in ovariectomized rats femoral diaphysis is similar with the evolution of transverse relaxation time centre of gravity T2,CG, a selected parameter to quantify the changes in intertrabecular cavities dimensions from onedimensional (1D) transverse relaxation time T2 distributions. Results: The analysis of histological images recorded for non-ovariectomized rats show that the treatment with simvastatin and fenofibrate has a negative effect on the dimension of the femoral diaphysis trabecular bone. The analysis of 1D T2 distributions show that the simvastatin and fenofibrate lipid-lowering drugs produce different effects on different particular sections of studied rat bones, i.e. proximal part of femoris, diaphysis or distal epiphysis. Conclusions: Finally, it is shown that the effects of the treatments are strongly dependent on the duration of treatment.
