Early irreversible osteonecrosis versus transient lesions of the femoral condyles: prognostic value of subchondral bone and marrow changes on MR imaging. - Lecouvet,F.E.; van de Berg,B.C.; Maldague,B.E.; Lebon,C.J.; Jamart,J.; Saleh,M.; Noel,H.; Malghem,J. (Amer J Roentgenol, 1998)