Scintigraphy and nuclear magnetic resonance imaging of the skeleton and bone marrow

Bone scintigraphy is the basic imaging modality in the diagnosis or exclusion of bone metastases and in follow-up of therapy. Magnetic resonance imaging (MRI) facilitates early diagnosis. However, compared to bone scan, MRI should be applied in selected cases only, for example prior to therapeutic difficult decisions. MRI gains increasing importance in diagnosis and staging of primary bone tumors; the application of scintigraphic methods remains unchanged. In systemic bone marrow disease, nanocolloid scintigraphy shows the whole extent of the disease, whereas MRI demonstrates regional abnormalities in more detail. In diagnosis, for planning of therapy and in follow-up of avascular necrosis of bone and bone marrow, MRI is routinely applied, to some extent on cost of scintigraphy. (orig.)