Comparison of dynamic contrast-enhanced magnetic resonance imaging and contrast-enhanced ultrasound for evaluation of the effects of sorafenib in a rat model of hepatocellular carcinoma

To compare the accuracy of contrast-enhanced ultrasound (CEUS) and Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for the assessment of changes in tissue vascularization as result of sorafenib treatment in a rat model of hepatocellular carcinoma (HCC). Male Buffalo rats with orthotopic liver tumors treated daily with 7.5 mg/kg sorafenib via oral gavage for 2 weeks (n = 9) were subject to DCE-MRI and CEUS 2 weeks after tumor implantation - right before treatment initiation - and also after treatment completion - right before tumor harvest. Untreated animals (n = 10) were used as control. Tumor tissue sections were stained for hematoxylin-eosin, pimonidazole, and CD34 for quantitative assessment of necrosis, hypoxia, and microvessel density (MVD), respectively. Of all the DCE-MRI parameters that were evaluated, only volume transfer constant (Ktrans) measurements were significantly lower in sorafenib-treated tumors (0.18 vs 0.33 min−1, p