[Magnetic resonance in hematological diseases. Imaging of bone marrow]

Magnetic resonance imaging (MRI) is a highly sensitive alternative to plain radiography, CT, and radionuclide studies for the imaging of normal and abnormal bone marrow. The cellularity and the corresponding fat/water ratio within the bone marrow show clear changes in haematological diseases. This enables MRI to detect differences between fatty, fibrotic, aplastic and hypercellular marrow in patients with haematological disease. MRI can evaluate the distribution of bone marrow disease because it has the potential for visualization of almost the entire bone marrow compartment. However, MRI is unable to establish the primary diagnosis in haematological bone marrow disease with diffuse hypercellular marrow. In case of insufficient biopsy, MRI can provide important differential diagnostic information as well as guidance for further biopsy attempts. MRI is a useful complement to morphological bone marrow evaluation in malignancies with focal marrow involvement, such as malignant lymphoma or metastases.