In case of agreement between the scans, the patient will proceed to clinical treatment as usual. In case of disagreement between the three modalities a MRI will be performed on the lesion of interest. If the results after MRI are still inconclusive a bone biopsy with emphasis on getting marrow tissue as well as bone matrix, will be performed. This will in many cases not be possible due to the size of the lesion and in these cases MRI will serve as reference standard.