[MR tomography of the lower limbs of children with diseases of the hematopoietic system].

In 41 children with disorders of the hematopoetic system 119 MR examinations of both tibiae and knees were performed (T1 and T2 spin-echo sequences and a T2 gradient-echo sequence). Before therapy bone marrow changes in leukemia were diffuse, and patchy during and after therapy. Signals in T2-weighted images were different for infiltrations, fibrosis, necrosis and siderosis. In 3 children suspected of suffering from osteomyelitis, Ewing-sarcoma or coxitis, MR examination was the first to show the correct diagnosis. Therefore in children indications for MR tomography should be handled more generously to win time for therapy. Using only a T1 spin-echo sequence and a T2 gradient-echo sequence screening of more than one region is capable of controlling bone marrow diseases.