Assessment of hemodynamics and quantitative evaluation of ferumoxides-enhancement MR imaging in liver tumors. Double-contrast study with ferumoxides and gadolinium

We evaluated the usefulness of a double-contrast enhanced study on magnetic resonance imaging (MRI) for hepatic function and hemodynamics in liver tumors. This study included 97 lesions in 81 patients with liver tumors. We carried out a double-contrast enhanced study on MRI using ferumoxides and gadolinium (Gd) chelate. Before and after the injection of ferumoxides, T2- and T1-WI were obtained under the same conditions. In addition, echo planar imaging (EPI) was performed, and the apparent diffusion coefficient (ADC) was calculated. Subsequently, hemodynamics and MR angiography (MRA) were evaluated by a Gd-enhanced study. In the quantitative evaluation of ferumoxides-enhancement, we calculated the T2-Lesion-Index [(post-lesion-region of interest (ROI) value minus pre-lesion-ROI value)/pre-legion-ROI value], T1-Lesion-Index [(post-lesion-ROI value minus pre-lesion-ROI value)/pre-lesion-ROI value], and ADC-Index (post-lesion-ADC/post-liver-ADC). An analysis of variance was used for the statistical analysis. In all patients, a Gd-enhanced dynamic study showed a good dynamic curve and MRA. The patients were classified according to hemodynamics into two groups: a hypervascularity group and a hypovascularity group. The T2-Lesion-Index was most markedly decreased in hemangioma, followed, in order, by focal nodular hyperplasia (FNH), hepatocellular carcinoma (HCC), and metastasis (Meta) in the hypervascularity group, and in HCC followed by Meta in the hypovascularity group. The T1-Lesion-Index showed the most marked enhancement in HCC, followed, in order, by FNH, Meta, and hemangioma in the hypervascularity group, and in Meta followed by HCC in the hypovascularity group. In the T2WI-Index, Meta was correlated with HCC, FNH, and hemangioma in the hypervascularity group. Significant differences were also observed in the T1WI-Index between HCC and hemangioma, and between FNH and hemangioma in the hypervascularity group, and in the ADC-Index between HCC and FNH and between FNH and hemangioma in the hypervascularity group. Significant differences in the ADC-Index were also found between HCC and Meta in the hypovascularity group. The double-contrast study on MR imaging was useful for evaluating hepatic function and hemodynamics in liver tumors, but did not accurately reflect hepatic function in the hypervascularity group with tumors showing vascular pooling. The vascularity and various indexes were supplementary, and were useful for the differential diagnosis of liver tumors. (author)