IMAGING OF THE INTRAMEDULLARY BONE INFARC TS AND THEIR COMPLICATIONS

Radiographic, CT, bone scan and MR patterns of the infarcts of the met aphyses and diaphyses of tubular bones and their main complications ar e presented. Bone marrow infarcts are located in the medullary cavity of long bones. They most often involve the lower limbs. They are commo nly associated with necrosis of the epiphyses and have common origin. In contrast to necrosis of the epiphyses, bone infarcts may present sp ecific complications. They are most often detected incidentally, becau se of their clinical latency. Radiographic and CT changes appear late, showing localized areas of increased density with irregular rims, or sharply demarcated shells of calcification. Earlier changes are demons trated by bone scan and MRI. MR pattern is characteristic, showing an area of hyposignal on T1- and T2-weighted sequences, with irregular ri ms, and sometimes small areas of fat signal. Their complications inclu de cystic formation and malignant degeneration (sarcoma and particular ly malignant fibrous histiocytoma). An unusual complication, infection involving bone infarcts is also presented.