Whole-body MR imaging for detection of bone metastases in children and young adults: Comparison with skeletal scintigraphy and FDG PET

Objective. The purpose of this study was to compare the diagnostic accuracy of whole-body MR imaging, skeletal scintigraphy, and 18F-fluorodeoxyglucos e (FDG) positron emission tomography (PET) for the detection of bone metast ases in children. Subjects and methods. Thirty-nine children and young adults who were 2-19 y ears old and who had Ewing's sarcoma, osteosarcoma, lymphoma, rhabdomyosarc oma, melanoma, and Langerhans' cell histiocytosis underwent whole-body spin -echo MR imaging, skeletal scintigraphy, and FDG PET for the initial stagin g of bone marrow metastases. The number and location of bone and bone marro w lesions diagnosed with each imaging modality were correlated with biopsy and clinical follow-up as the standard of reference. Results. Twenty-one patients exhibited 51 bone metastases. Sensitivities fo r the detection of bone metastases were 90% for FDG PET, 82% for whole-body MR imaging, and 71% for skeletal scintigraphy; these data were significant ly different (p < 0.05). False-negative lesions were different for the thre e imaging modalities, mainly depending on lesion location. Most false-posit ive lesions were diagnosed using FDG PET. Conclusion. Whole-body MR imaging has a higher sensitivity than skeletal sc intigraphy for the detection of bone marrow metastases but a lower sensitiv ity than FDG PET.