Administration and dosage of iohexol, a nonionic contrast medium, for dynamic renal computed tomography

We investigated the optimal method of administering iohexol, which contains 300 mg iodine/ml (Omnipaque 300), a nonionic contrast medium, to maintain adequate renal contrast while reducing artifacts during dynamic CT scanning. In this study, 76 patients with renal disease received 10-50 ml of iohexol as follows: group I (14 patients), 20 ml injected as an intravenous bolus for 5 sec, followed by 30 ml intravenous drip infusion for 5 min; group II (18 patients), bolus of 20 ml injected for 5 sec; group III (13 patients), 20 ml diluted with sterile water (total volume 40 ml), and injected as a bolus for 8 sec; group IV (15 patients), 20 ml injection for 5 sec followed by intravenous drip infusion of 200 ml of Hartmann-Ringer's solution given at maximum speed; and group V (14 patients), 10 ml diluted with sterile water (total volume 20 ml) injected as a bolus for 5 sec. We found that corticomedullary differentiation was most distinct on the images obtained from group IV. We concluded that a lower concentration of iohexol (150 mg iodine/ml) given by intravenous fluid loading can provide superior CT images.