They were randomly assigned to 3 groups , group A ( n = 15 ) were scanned in 120 kVp with 350 mgI/ml iodinated contrast agent mode , group B ( n = 15 ) were scanned in 100 kVp with 350 mgI/ml iodinated contrast agent mode , group C ( n = 15 ) were scanned in 100 kVp with 270 mgI/ml iodinated contrast agent mode .