Quantitative dynamic contrast-enhanced magnetic resonance imaging in a VX2 rabbit liver tumour model using different gadolinium-based contrast agents: comparison of DCE-MRI quantitative results between Magnevist and Eovist

Quantitative dynamic contrast enhanced MRI (DCE-MRI) can offer information related to tumour perfusion and permeability (K(trans)), rate constant (K(ep)), extravascular extracellular volume fraction (V(e)) and distribution volume (V(d)). Different types of gadolinium-based contrast agents (GBCAs) may traverse the vascular wall with different velocities owing to their physicochemical characteristics. The purpose of this article was to compare the DCE-MRI quantitative results (K(trans), K(ep), V(e) and V(d)) between Magnevist and Eovist in a VX2 rabbit liver tumour model. Sixteen rabbits (body weight, 3 Kg; random gender) containing implanted hepatic VX2 carcinomas were randomly divided into two groups based on the regimen of MRI contrast agent administered, eight rabbits in each group. All rabbits underwent a liver DCE-MRscan before tumour transplantation. Fourteen days after tumour transplantation, the eight rabbits in Group A (Magnevist group) underwent a liver DCE-MR scan in a 3.0 T Magnetom Verio MR scanner (Siemens Healthcare, AD, Germany) after the administration of Magnevist at the flow rate of 1 ml s(–1). The Group B rabbits underwent the same scan except for the administration of Eovist at the same flow rate. Twenty-four hours after the initial DCE-MRI, repeat DCE-MRI was performed with the cross-over GBCA at the same flow rate in each group. Every rabbit received 0.6 ml GBCA (0.2 ml Kg(–1)) during each DCE-MRI. K(trans), K(ep), V(e) and V(d) were measured in the tumour lesion and compared with normal liver tissue in the same slice. A pathologic examination was also performed. Hepatocellular carcinoma was diagnosed in all 16 rabbits by pathologic examination. There were no significant differences in K(trans), V(e), K(ep) and V(d) between the two groups of rabbits (p > 0.05). The K(trans), V(e), K(ep) and V(d) of the VX2 rabbit liver tumour model were significantly higher than the normal liver parenchyma (0.742 ± 0.086 vs 0.027 ± 0.002, 7.345 ± 0.043 vs 6.721 ± 0.035, 0.101 ± 0.005 vs 0.101 ± 0.005, 0.419 ± 0.083 vs 0.037 ± 0.005, respectively; p < 0.01). The K(trans), V(e) and V(d) of Eovist group were significantly higher compared with the values in the Magnevist group (0.116 ± 0.016 vs 0.010 ± 0.002, respectively, p < 0.01; 0.101 ± 0.005 vs 0.004 ± 0.0009, respectively, p < 0.01; 0.419 ± 0.083 vs 0.037 ± 0.005, respectively, p < 0.001). There was no significant difference in K(ep) between the Eovist and Magnevist groups (7.345 ± 0.043 vs 6.721 ± 0.035, respectively; p > 0.05). In the VX2 rabbit liver tumour model, DCE-MRI performed with different types of GBCA can develop different quantitative results with respect to K(trans), V(e) and V(d). The liver-specific GBCA, Eovist, is more sensitive than the general GBCA, Magnevist, in detecting tumour perfusion and permeability.