Gadopentetate dimeglumine and iopromide were used in density measurements. Using 20 mL disposable syringes, serial dilutions of Gd and iopromide with saline were performed. Computed tomography scanning was done and the attenuation of each was recorded as mean Hounsfield units using region of interest analysis. Clinical trials were done in twelve patients with the following types of angiogram or intervention: hemodialysis access, percutaneous biliary drainage, percutaneous nephrostomy, cerebral angiography and transarterial chemoembolization (TACE) in hepatocellular carcinoma. The density of 1 : 1 diluted Gd was nearly equal to that of 1 : 4 dilution of iopromide, and that of pure Gd was similar to or less than that of 1 : 1 dilution of iopromide. Serum creatinine level was not elevated in any of the patients.

Gd is a safe alternative agent in patients with contraindications to iodinated contrast materials. Pure Gd without dilution is the most clinically useful concentration.