[Optimal dosage of contrast material in brain enhanced CT].

PURPOSE: To assess the optimal contrast dosage for brain enhanced CT.

MATERIALS AND

METHODS

A total of 150 patients were randomly assigned to two groups. The patients were also divided by body weight into three groups (< 50 kg, 50-59.9 kg and > or = 60 kg). A total of 100 ml (in 77 patients) or 50 ml (in 73 patients) of contrast material (iopamidol 300 mgI/ml) was intravenously administrated at a speed of 1 ml/sec. Three diagnostic radiologists evaluated image quality by five- or two-stage scoring systems with special attention given to enhancement of the anterior and middle cerebral arteries. CT values of the basilar artery were also measured.

RESULTS

In visual evaluation by the five-stage scoring system, image quality with 100 ml of contrast material was better than that with 50 ml in all body-weight groups, although no difference was observed with the two-stage scoring system in patients weighing less than 60 kg. CT values of the basilar artery were higher in patients given 100 ml than in those given 50 ml regardless of weight groups.

CONCLUSION

The image quality of brain CT using 50 ml of contrast material is sufficient for correct diagnosis in patients with a body weight of less than 60 kg.