One hundred thirteen consecutive patients randomly underwent three protocols for dual-phase renal CT angiographic imaging : high-iodine-load ( @ mg iodine per kilogram of body weight at @ kVp ) ; moderate-iodine-load ( @ mg iodine per kilogram of body weight at @ kVp ) ; and low-iodine-load ( contrast agent injection initially prepared at @ mg iodine per kilogram of body weight but stopped immediately after bolus-tracking trigger at @ kVp ) scanning .