Gadobenate dimeglumine--a new contrast agent for MR imaging: preliminary evaluation in healthy volunteers.

Gadobenate dimeglumine (formerly known as Gd-BOPTA) is a recently developed paramagnetic contrast agent that undergoes biliary as well as renal excretion. It may, therefore, be useful in MR imaging of the liver. Its safety, tolerance, and usefulness in visualizing hepatobiliary structures were studied in eight healthy subjects. Axial abdominal images were obtained with T1-weighted spin-echo and gradient-echo sequences at 1.5 T before and after IV administration of gadobenate dimeglumine in doses of 0.005, 0.05, 0.1, and 0.2 mmol/kg body weight. Two subjects received each dose. Administration of 0.1 mmol/kg resulted in a maximum liver enhancement of 149% on the gradient-echo sequence and of 90% on the T1-weighted spin-echo sequence 60 min after injection. The contrast enhancement of the liver remained virtually constant for 2 hr. The signal-to-noise ratio of the biliary tract increased from 38 to 121 after 2 hr on gradient-echo images. In addition, there was significant contrast enhancement of the kidneys. Optimal visualization of the liver parenchyma was achieved with doses of 0.05 and 0.1 mmol gadobenate dimeglumine/kg. Mild to moderate side effects such as nausea and retching, a sense of warmth at the infusion site, and transient pruritus lasting 1 min were reported by three (38%) of the subjects. The initial results of the first application of gadobenate dimeglumine in humans are encouraging because the contrast agent appears to be reasonably well tolerated at the doses appropriate for hepatobiliary imaging. Further clinical studies of this contrast agent are warranted to assess its effect on liver lesion conspicuity and the frequency with which side effects occur.