A comparison of radionuclide scanning and computed tomography in metastatic lesions of the brain.

Forty-seven patients with a final diagnosis of brain metastases were studied with both computed tomography (CT) and radionuclide (RN) scanning. Fifty-three percent of these patients also underwent contrast enhanced CT. Radionuclide scanning detected 94% of the cases, while CT without contrast enhancement was positive in 89%. The addition of contrast material to the CT examination increased the total sensitivity of CT to 94% and permitted the detection of two cases that were falsely negative on RN scanning and CT without contrast. With both techniques, lesions in the cerebral hemispheres were detected more readily than infratentorial lesions. Radionuclide scanning was less sensitive than CT without contrast in the detection of multiple metastases. Contrast enhanced CT should be used in all cases of suspected cerebral metastases unless contraindicated.