RT Journal A1 Barzel E, Haller JO, Wood BP T1 RAdiological cases of the month JF American Journal of Diseases of Children JO American Journal of Diseases of Children YR 1989 FD May 1 VO 143 IS 5 SP 623 OP 624 DO 10.1001/archpedi.1989.02150170125039 UL http://dx.doi.org/10.1001/archpedi.1989.02150170125039 AB A 17-year-old girl complained of pain in the right hip one year after renal transplant surgery. She had been given high-dose steroids because of early episodes of acute rejection. Physical examination revealed only slight limitation of motion of the right hip. Laboratory data were unremarkable. Roentgenograms of the right hip were normal. A magnetic resonance scan of the pelvis was performed. Selected T1- and T2-weighted coronal images of the pelvis are shown (Figs 1 through 3).Denouement and Discussion  Osteonecrosis of the Femoral Head Diagnosed by Magnetic Resonance Imaging  Osteonecrosis, also referred to as avascular necrosis and ischemic necrosis of bone, is a complication of steroid use. It results from small blood vessel alteration and infarction of the bone marrow. The infarction may be caused by physical disruption of vessels (from trauma), thrombosis (in sickle cell disease), or vascular compression (from