Magnetic resonance imaging of intracranial tumors in children and adolescents.

Magnetic resonance (MR) scans were reviewed of 25 children and adolescents from the age of 9 months to 18 years referred with a suspected or proven diagnosis of intracranial tumor. Twenty-one of these children had MR scans positive for tumor. Histology was available in 14. The other seven patients were managed clinically as cases of cerebral tumor, although histologic confirmation was lacking. Seventeen tumors displayed an increase in both T1 and T2. One dermoid tumor and part of another displayed a very short T1 (less than that of white matter). Two hamartomas had T1s similar to that of gray matter and a small increase in T2. Four of the children did not show MR or computed tomographic (CT) evidence of intracranial tumors. Follow-up of these cases for 1-23 months after the MR and CT studies revealed no subsequent clinical evidence of tumor. MR scans showed more extensive abnormality than did third-generation CT scans in eight of 10 cases and more extensive abnormality than EMI CT 1010 scans in 10 of 11 cases. Mass effects were better demonstrated in 14 of the 16 patients in whom they were seen. CT demonstrated calcification better than did MR in all four cases in which it was identified. The tumor-edema interface was shown better on CT in each of the three cases with contrast enhancement on CT. MR is a sensitive method of evaluating intracranial tumors in children and adolescents.