Hepatocellular Carcinoma: Correlation Of Dynamic Gadolinium-enhanced MR Imaging Findings With Nuclear DNA Content

Objective:To study the correlation of dynamic MRI enhancement features with nuclear DNA content in hepatocellular carcinomas(HCC).Materials and methods: From July 1999 to November 2002,43 patients with pathologically confirmed HCC were enrolled in this study. MR imaging examinations were performed on LOT MR imager. T1-weighted GRE, T2-weighted TSE and dynamic enhancement (the same as Tl-weighted) sequences were employed. The features of the HCCs wre evaluated. The enhancement types of HCC were classified into four categories, type I:hyper- or isointensity on arterial phase(AP) and hypointensity on portal phase(PP); type II: hyper- or isointensity on both AP and PP; type III: hypointensity on AP and iso- or hyperintensity on PP; type IV: hypointensity on both AP and PP. Enhancement type, pattern and degree of enhancement on AP, size, capsule, necrosis, satellite nodules and the portal vein invasion of HCC were analyzed. DNA index(DI) and S-phase fraction(SPF) were measured by Flow Cytometry with paraffin-embedded specimens of HCC. The relationship between dynamic MRI features and nuclear DNA content of HCC was analyzed.Results: The aneuploid rate in HCC was 77%(33/43). Of 43 cases, there were 29 cases of enhancement type 1,12 cases of type II, each one of type III and type IV. SPF and DI of enhancement type I were significantly higher than those of type II (p=0.001; p=0.009). The statistical differences were documented between DI of HCC with peripheral and non-peripheral enhancement (p=0.005), markedly and slightlyenhancement (p=0.038), homogeneous and inhomogeneous enhancement (p <0.001). DI of tumor with diameter>5.0cm, tumor necrosis ,satellite nodules and without tumor capsule were significantly higher than that of tumor diameter < 3.Ocm (p=0.002), without tumor necrosis (p=0.026) and satellite nodules (p=0.005), with capsule (p=0.027). There wre no differences for DI of HCC between tumor diameter < 3.0cm and diameter in 3.0cm-5.0cm(p=0.192), between tumor diameter in 3.0cm-5.0cm and diameter> 5.Ocm(p=0.084). AT multiple linear regression's and logistic regression's analyses, tumor size, tumor capsule, enhancement type and enhancement pattern were correlate with DI, only enhancement type was correlate with SPF. According to Edmonson-Steiner 4 grades system, DI and SPF of HCC in Grade III, IV were higher than in Grade I , II (p=0.001; p=0.018). Tumor differentiation of enhancement type I was worse than that of type II (p=0.024). Conclusion: The features of dynamic MRI enhancement were correlate with nuclear DNA content and the degree of tumor cell differentiation of hepatocellular carcinomas in a certain degree. They could indirectly reflect the malignant biological behavior of HCC.