Potential for differential diagnosis with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging in experimental hepatic tumors.

RATIONALE AND OBJECTIVES

To investigate whether dynamic and delayed magnetic resonance imaging (MRI) with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA), a hepatobiliary MRI contrast agent, has potential for the differential diagnosis of experimental hepatic tumors.

METHODS

Twelve male rats received N-nitrosomorpholine solution as drinking water to induce hepatic tumors. After injection of Gd-EOB-DTPA, rats were subjected to dynamic and delayed MRI. The relative enhancement (RE) was calculated, and the time of the maximum RE (Tmax) was evaluated. After MRI, liver was histologically analyzed.

RESULTS

One hundred sixty-three hepatic tumors 3-12 mm in diameter were induced after 18 weeks of treatment with 0.01 wt/vol% of N-nitrosomorpholine, and 81 of them were evaluated. The RE in hyperplastic nodules (HPNs) was significantly higher than that in moderately or poorly differentiated hepatocellular carcinomas (HCCs) in the late phase, whereas there was no significant difference in RE between well-differentiated HCCs and HPNs. The average Tmax in HPNs was about 13 minutes, whereas that of each differentiated HCCs was about 1 minute.

CONCLUSIONS

It was possible to differentiate benign HPNs and malignant HCCs (especially well-differentiated HCCs) by evaluating the change of RE or comparison of Tmax with Gd-EOB-DTPA-enhanced MRI.