MR imaging of the body in pediatric oncology

Fifty-five magnetic resonance (MR) examinations of the body were performed in pediatric oncology patients. In 21 cases, additional T1-weighted images were obtained after the intravenous injection of Gd-DTPA. The neoplasms included neuroblastoma, rhabdomyosarcoma, germ cell tumor, liposarcoma, Ewing sarcoma, and other entities. MR findings were correlated with the results of other imaging techniques and surgical findings. In the primary evaluation of eight cases of soft-tissue tumors, the authors found significant enhancement with Gd-DTPA. The effect of contrast enhancement with increasing signal intensity on T1-weighted images improved the definition of tumor size and its relationship to adjacent organs. Follow-up studies during the course of the treatment with radiation therapy and/or chemotherapy showed a variable degree of tumor reduction due to differences in tumor response. Gd-DTPA improved demonstration of tumor necrosis. Recurrence of neoplasm after treatment was seen in five cases and confirmed at surgery or biopsy. All of these lesions showed high signal intensity on T1-weighted images, produced by sufficient enhancement with Gd-DTPA