Comparison between liver-specifc and vasculo-interstitial contrast agents in the detection of solid benign focal liver lesions

Purpose: To verify the diagnostic potentials of different paramagnetic and superparamegnetic contrast media in detecting and characterizing solid benign focal liver lesions. Methods and materials: Twelve patients with US evidence of solid benign focal liver lesions (8 cases of focal nodular hyperplasia and 3 cases of adenoma) were submitted to MR examination. 3 different constrast agents were employed in all cases Mn-DPDP (Teslascan, Guerbet), Gd-BOPTA (MultiHance, Bracco) and SPIO particles (Endorem, Guerbet). The study was carried on employing a 1.5 T unit (GE Horizon), using breath hold T1-w SPGR sequences before and after (fat-sat) i.v. injection of Mn-DPDP and Gd-BOPTA (dynamic and hepato-specific phase), T2-w sequences (Single Shot Half Fourier) and T2*-w fast GE sequences after SPIO particles injection. Biopsy was performed in all cases. Results: All lesions appeared isointense with respect to normal parenchyma before and after i.v. injection of Mn DPDP and during the liver-specific phase of Gd-BOPTA due to the up-take in the hepatocytes. Dynamic study after i.v. injection of Gd-BOPTA showed a rapid and strong enhancement during the arterial phase in all of them. The absence of RES inside the tree adenomas determined a hyperintense appearance, upon a dark liver, using the SPIO particles, all FNH instead appeared to be isointense to the liver. Biopsy confirmed MRI findings in all cases. Conclusion: We consider all MR contrast agents useful in confirmation of the benignity of focal lesions. The agent selected depends on each particular case. In the case of suspicion of adenoma we suggest the use of hepatocytic agents.