Musculoskeletal manifestations of chronic anemias.

This article provides an overview of the current use of diagnostic imaging modalities in the evaluation of a heterogeneous group of disorders causing chronic anemias by impaired blood cell production (inherited bone marrow failure syndromes of childhood, aplastic anemia and myelodysplastic syndromes, β-thalassemia) or increased blood cell destruction (sickle cell disease). During the course of these disorders, various musculoskeletal abnormalities can be encountered, including marrow hyperplasia, reversion of yellow marrow to red marrow, growth disturbances, and, occasionally, extramedullary hematopoiesis. Diagnostic imaging may help the clinician to identify specific complications related to either the disease (e.g., bone infarction and acute osteomyelitis in sickle cell disease) or transfusion (e.g., iron overload due to increased hemolysis) and iron chelation (e.g., desferrioxamine-related dysplastic bone changes and deferiprone-related degenerative arthritis) treatments. In this field, magnetic resonance imaging plays a pivotal role because of its high tissue contrast that enables early assessment of bone marrow changes before they become apparent on plain films or computed tomography or metabolic changes occur on bone scintigraphy or positron emission tomography scan. Overall, familiarity with the range of radiological appearances in chronic anemias is important to diagnose complications and establish appropriate therapy.