Four children, ages 4-10 yrs, with brain tumors treated at the Univ of Calgary, Alberta, Canada, developed alterations in consciousness and vital signs after contrast-enhanced cranial computed tomography (CT). Each had increased intracranial pressure but was alert and coherent before the IV injection of diatrizoate meglumine 60%, 2 to 2.5 ml/kg. Two children had generalized seizures and two died immediately after the procedure. The authors caution that CT with contrast should be reserved for children who warrant the additional procedure and when the necessity for urgent neurosurgical intervention is not resolved after the nonenhanced scan. 
COMMENT. Reactions to contrast enhanced CT are sufficiently frequent to avoid its use as a routine neurodiagnostic procedure, especially in children with brain tumor and raised intracranial pressure. Neurologists requesting a CT in nonsurgical cases will usually specify a pre-infusion scan only, unless the diagnosis suspected requires enhancement of the lesion. Magnetic resonance imaging is a noninvasive technique that provides images of comparable or superior quality without exposure to contrast effects or ionizing radiation. When available, MRI should be used in preference to contrast-enhanced CT, particularly in children.