MRI of bone metastases.

Some knowledge of MR theory is required to be able to achieve high contrast between bone metastases and normal marrow. Three factors are used in MR to diagnose bone metastases; fat-water distribution, artifacts induced by bone trabeculae, and uptake of contrast medium. Using MR-histological correlations based on specimens of the lumbar spine, and studies of patients, we explain the advantages and limitations of sequences studying fat and water (spin-echo T1, STIR, in- and out-of-phase gradient echo, fat presaturation), bone trabeculae (gradient echo with long TE), and the injection of contrast medium.