Primary hepatocellular carcinoma: investigation on the correlation between enhancement index on MnDPDP enhanced MRI and tumor differentiation

Objective: To explore the correlation between the enhancement index of HCC on MnDPDP enhanced MRI and the tumor differentiation. Methods: The enhancement indices of 43 HCCs in 34 cases detected on MRI with MnDPDP confirmed surgico-pathologically were analyzed and compared with the HCC differentiation. The 24-hour delayed T1W SE images enhanced with MnDPDP were employed in this study. The enhancement findings of the lesion foci at their midaxial sections in 43 HCCs were blindly divided into two groups: homogeneity and heterogeneity by 3 experienced radiologists, and for the latter, the regions with different signal intensities (low, iso- or high) were scored 1 to 3 credits. Then ,all the lesions including the homogeneous ones were scored and the credits were weighted proportionally by the size of areas in which the different signal intensity dominated. At last, the scores for different areas were summed up to obtain 'Enhancement Index' for the HCC focus respectively. And eventually, the enhancement index for HCC was compared with HCC pathologic grading. The sites for specimen collection were corresponding to the regions with different signal intensities, and the conjunction area between the tumor and liver was also examined pathologically. Results: The overall sites for pathologic examination were 125 for the 43 HCCs. The sites of HCCs dominated by fatty changes (2), hyaline-cells (3) and necroses (7) were rejected. Edmondson and Steiner grading was performed for the rest 113 sites of HCC specimens as follows: I(13), I- II(7), II(50), II-III(22), III(19), III-IV(1), and IV(1). On MnDPDP enhanced MR images, the regions of HCCs in high, isointense, and low signal intensity were 81, 17, and 15, respectively. There was a significant correlation between the signal intensity on MnDPDP enhanced MRI and the tumor differentiation of HCC on region-by-region basis (χ2=26.75, P<0.005). And the HCC enhancement index with MnDPDP was significantly correlated with the tumor differentiation (χ2=7.94, P<0.005). Conclusion: The enhancement index of HCC on MnDPDP enhanced MRI was well correlated with the tumor differentiation