Immature bone infarcts: findings on plain radiographs and MR scans.

We studied the plain film findings in eight patients with immature bone-marrow infarction and correlated the findings with those of MR imaging in four of the cases. Seven patients had underlying systemic disease, including sickle cell disease (two), systemic lupus erythematosus (two), acute lymphocytic leukemia (one), non-Hodgkin lymphoma (one), and renal transplantation (one). In one patient, the bone infarct was idiopathic. Plain films in three of the eight cases were misinterpreted as showing aggressive lesions (i.e., malignancy or infection), and these patients underwent a biopsy that proved the diagnosis of bone infarction. In the other five cases, the diagnoses were established by clinical follow-up. The plain film findings in all eight cases consisted of subtle, mottled, ill-defined radiolucencies in the diametaphyseal region. Four of the patients had mild sclerosis. MR imaging in all four cases in which it was performed showed a central area with high or intermediate signal with a serpentine, thin, low-signal border. The lesions shown by MR imaging corresponded to the areas of abnormality on the plain films and had an appearance similar to that of previously reported bone infarcts. Our experience suggests that in patients with nonspecific subtle radiographic bone changes and an underlying systemic disease, MR imaging is helpful in establishing the diagnosis of bone marrow infarction.