The Iron Content of Hepatocellular Carcinoma Associated Nodules: Study of Histopathology and MR Imaging

Objective To explore the clinical value of MRI imaging of measuring the iron content for hepatocellular carcinoma (HCC) associated nodules. Methods 55 male Wistar rats were randomly allocated into a treatment and a control group, which were administered with diethyl nitrosamine (DEN) and the sterilized tap water. According to the macro pathology differences, the treatment groups were divided into three groups: cirrhotic nodules group, cirrhotic nodules with HCC group, and HCC group; According to the micro pathology differences, the treatment groups were divided into four groups: regenerative nodules (RN) group, low grade dysplastic nodules (LGDN) group, high grade dysplastic nodules (HGDN) group, and HCC group. After 13 weeks, the rats were scanned by MRI T2WI and T2*WI. The next day all rats were sacrificed for histological tests and tissue iron level determination. The correlations were statically analyzed between the values of T2, T2* and the grades of iron stain, the quantification of tissue iron. Results With macro pathology observation, the values of T2, T2* among control group (normal rats), cirrhotic nodules group, cirrhotic nodules with HCC group, HCC group were increased, while the quantification of tissue iron were decreased. Significant differences were found for T2, T2*and quantification of tissue iron in three groups (P<0.05). Low-grade negative correlations could be found between T2, T2* and quantification of tissue iron in whole samples (r₁=-0.364, P1=0.000; r₂=-0.245, P2=0.018). With micro pathology observation, there were significant differences among the control (normal rats), RN, LGDN, HGDN, and HCC groups for the grades of iron stain both in the essence and the interstitial (P<0.05). After comparison each two groups, significant differences were found among some groups for the grades of iron stain both in the essence and the interstitial (P<0.05). Generally the grades of iron stain for HCCs were lower than non-HCC both in the essence and the interstitial. Conclusion Negative correlation between T2, T2* and iron content demonstrats that T2 and T2* could roughly estimate the iron content in the cirrhotic nodules. T2 and T2* measurements could contribute to differential diagnosis of HCC nodules.