In this work we evaluate the relative merits of MRI and CT to “gold standard” histopathology assessment, with regard to bone tumor metastases. We also investigate the profound effect that decalcification process has on tumor/bone morphology. MRI shows differences in tumor shape before and after decalcifications, however the differences in total tumor volume were smaller than 5 percent. Co-registered microCT images and MR images exhibit displacement of bone-matrix after decalcification. The question of co-registration between all three modalities remains open, however we believe our algorithm minimizes registration errors.