Iomeprol, a new nonionic contrast medium, was administered at concentr
ations of 300 mgI/ml, 350 mgI/ml, and 400 mgI/ml to 1939 Japanese pati
ents. The radiographic efficacy, the incidence of heat sensation and t
he incidence of pain were evaluated. The radiographic efficacy was rat
ed as excellent in 80.6% and good in 17.5% of 1017 cases of convention
al arteriography, excellent in 75.6% and good in 22.2% of 267 cases of
IADSA or IVDSA, excellent in 78.3% and good in 19.6% of 384 cases of
intravenous urography and excellent in 68.6% and good in 28.8% of 271
cases of CT enhancement. There was no statistical difference in radiog
raphic efficacy between the sites of arteriography. Heat sensation was
mild or moderate in 43.4% and severe in 0.2% of cases requiring intra
-arterial injection, and mild or moderate in 50.7% of cases requiring
intravenous injection. There were no cases of severe heat sensation fo
llowing intravenous injection. The incidence of pain was low (mild 4.2
%, moderate 0.7% and severe 0.1%) with intra-arterial injections. It i
s concluded that iomeprol is an excellent radiographic contrast medium
for intravenous urography, CT enhancement and various forms of angiog
raphy.