A new imaging modality combining CT and tomographic bone scintigraphy (SPECT/CT) has enabled the combination of functional and anatomical imaging. Its use in cancer patients has not yet been evaluated or validated against a relative gold stand or clinical follow up. The purposes of this study are: 1: to validate the use of conventional planar bone scintigraphy and SPECT combined with low-dose or diagnostic CT and compare this to 3 Tesla MRI and clinical follow up. 2: to compare the specificity of low-dose and diagnostic CT, respectively, combined with bone SPECT. 3: to construct an algorithm for optimal evaluation of disease dissemination in breast cancer patients