Comparison of Gd‐EOB‐DTPA and Gd‐DTPA for contrast‐enhanced MR imaging of liver tumors

A new hepatobiliary contrast agent for magnetic resonance (MR) imaging, gadolinium‐ethoxybenzy1 (EOB)‐diethylemetriaminepentaacetic acid (DTPA), was compared with Gd‐DTPA to define the potential for improving tumor‐liver contrast in a rodent liver adenocarcinoma model. With a T1‐weighted spin‐echo sequence, the contrast‐to‐noise ratio (C/N) for tumor before contrast agent administration was 5 (arbitrary units), the tumor appearing slightly hypo‐intense with respect to liver parenchyma. After Gd‐DTPA injection (0.1 mmol/kg), tumor enhanced more strongly than liver, resulting in an equalization of tumor and liver signal intensities and a decline in C/N to zero at 3 minutes after injection. After Gd‐EOB‐DTPA injection (0.1 mmol/kg), liver enhanced more strongly than tumor. Five minutes after injection, C/N increased from 5 to 25 and remained above 17 for 50 minutes. The data indicate that Gd‐EOB‐DTPA yields higher and more prolonged tumor‐liver contrast than Gd‐DTPA on T1‐weighted spin‐echo images. The high liver‐tumor contrast after Gd‐EOB‐DTPA administration should prove clinically advantageous for MR imaging detection of focal hepatic masses.