Contrast-enhanced cranial computed tomography in magnetic resonance imaging era.

OBJECTIVE To evaluate the usefulness of intravenous contrast administration in cranial computed tomography (CT) in a general hospital with a magnetic resonance imaging (MRI) facility, and to establish a protocol to determine which patients would benefit most from using contrast-enhanced cranial CT. SUBJECTS AND METHODS Five hundred and forty-seven patients who underwent routine nonenhanced CT (NECT) and contrast-enhanced CT (CECT) of the brain between June 1997 and June 2001 were divided into three groups. Group A: 496 patients in whom CECT was done in spite of normal NECT; group B: 16 patients in whom CECT was considered necessary irrespective of NECT findings, and group C: 35 patients in whom NECT was abnormal and CECT was performed. RESULTS Contrast-enhanced cranial CT changed and/or confirmed the diagnosis in 1 of 496 in group A, 2 of 16 in group B, and 12 of 35 in group C, thereby indicating that CECT was useful in the diagnosis of groups B and C. CONCLUSION CECT is unlikely to be useful in patients with normal NECT in the appropriate clinical setting. A protocol is presented for the use of contrast media in cranial CT in a general hospital with an MRI facility. Using this protocol only 9.7% of patients for cranial CT would have needed CECT, resulting in considerable cost savings without affecting the quality of the service to the patient in a general hospital.