Objective: To determine the effect of corticosteroid treatment and severe acute respiratory syndrome (SARS) infection itself on the marrow conversion in the proximal femoral marrow in the recovered patients of health care workers with SARS.
Methods: The distribution of proximal femoral marrow on MR imaging of 148 health care workers with recovered SARS including 106 cases treated with varied dosage of steroids and 42 cases without steroid, and 97 age and sex matched health adults as controls were observed. The index of marrow conversion (signal intensity of the femoral neck and intertrochanteric area divided by signal intensity of the greater trochanter multiplied by 100%) was quantitatively measured and compared between SARS patients treated with steroid and without steroid and the normal control group.
Results: In 106 cases treated with steroid of the 148 health care workers, femoral head osteonecrosis was found in 4 cases, bilateral femoral marrow edema in 2 cases, femoral marrow infarction in 1 case. The index of marrow conversion in the normal controls, in SARS patients treated without and with steroids was (79.4 +/- 6.8)%, (86.9 +/- 7.4)%, (88.6 +/- 5.9)%, respectively. There was significantly statistical difference between groups (P < 0.05).
Conclusion: In addition to fat conversion in the proximal femoral marrow due to steroid treatment, the infection of SARS itself may promote an excessively conversion of the red marrow to yellow marrow of the femoral neck in SARS patients.