Effect of hematopoietic growth factors on MR images of bone marrow in children undergoing chemotherapy.
OBJECTIVE
To evaluate the effects of hematopoietic growth factors on magnetic resonance (MR) image signal intensity (SI) of bone marrow in children undergoing neoadjuvant chemotherapy for musculoskeletal malignancies.


METHODS
Blinded evaluations were performed of T1-weighted and short inversion time inversion recovery images of the pelvis and/or lower extremities of 15 patients undergoing chemotherapy, with or without granulocyte or granulocyte-macrophage colony-stimulating factor.


RESULTS
Four of the 11 patients who received growth factors initially had hematopoietic marrow SI that did not change during therapy. All seven with initially fatty marrow had SI changes consistent with reconversion to hematopoietic marrow that coincided temporally with increases in absolute neutrophil counts from minimums of 0-2,580/mm3 to maximums of 10,858-45,880/mm3. The four patients who did not receive growth factors had no MR imaging changes in initially hematopoietic (n = 1) or fatty (n = 3) marrow.


CONCLUSIONS
Hematopoietic activity induced by growth factors can produce changes in bone marrow SI that may simulate bone marrow involvement by musculoskeletal tumors.
Fletcher
B D
BD
Department of Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, TN 38101.
Wall
J E
JE
Hanna
S L
SL
D000293:Adolescent; D001853:Bone Marrow / Q000187:drug effects / Q000473:pathology*; D001859:Bone Neoplasms / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D005266:Femoral Neoplasms / Q000628:therapy; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000627:therapeutic use*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009135:Muscular Diseases / Q000628:therapy*; D012516:Osteosarcoma / Q000628:therapy; D010386:Pelvic Neoplasms / Q000628:therapy; D012983:Soft Tissue Neoplasms / Q000628:therapy*
D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor