Value of high contrast medium dose in brain CT.

Fifty-five patients with brain lesions were examined by computed tomography (CT) after two doses of contrast medium: a bolus injection of 65% meglumine diatrizoate, 1 ml/kg, and a bolus injection of 65% meglumine diatrizoate, 1.5 ml/kg, in combination with an infusion of 250 ml meglumine iodamide containing 110 mg I/ml. The studies were usually performed 2 days apart and were analyzed by three radiologists. In 25 patients, one or more of the radiologists changed the diagnosis or the number or size of the lesions when the two scans were observed separately. In three patients, the primary tumor or metastases were seen in the study performed after the higher dose only, and, in two other patients having cerebral metastases, a greater number of metastases were detected in the high dose study. The lower dose containing 15 to 31 g iodine (306 mg iodine/kg) seems to be inadequate in CT of the brain.