Imaging the complications of bone marrow transplantation in children

Bone marrow transplantation is frequently performed to restore hematologic and immunologic competence after chemotherapy and radiation therapy for a range of childhood malignancies, as well as to treat various congenital conditions in which hematologic and immunologic functions are depressed or absent. Potentially devastating complications may occur during the pre-engraftment period after bone marrow transplantation, when marrow aplasia may supervene for several weeks until engraftment occurs, as well as during the post-engraftment period (the 3 months after engraftment) and in subsequent months and years. Complications of bone marrow transplantation may be classified either according to the time interval between transplantation and the occurrence of the complication or according to the organ system affected. The range of complications that may affect the central nervous system and the rest of the body may be detected with ultrasonography, computed tomography, and magnetic resonance imaging. Neurologic, paranasal sinus, pulmonary, and abdominopelvic complications all may be seen after bone marrow transplantation. Graft-versus-host disease and lymphoproliferative disorders also may occur. The increasing use of bone marrow transplantation mandates that the radiologist be familiar with the full range of potential complications and their imaging appearances.