Abstract: Objective To study the difference of magnetic resonance imaging（MRI） scan and enhanced features of patients with primary liver cancer （PLC） and focal nodular hyperplasia （FNH）. Methods 26 patients with FNH and 36 patients with PLC between July 2014 and June 2016 were enrolled in this study,and all of them finished MRI check-up. Lesion distribution and imaging manifestation were compared between the two lesions. Results The proportion of lesions in the left lobe and right lobe in FNH foci were 30.8% and 69.2%）,not statistically different as compared with PLC foci（38.9% and 61.1%,P>0.05）,while the foci under hepatic capsule in FNH was 46.2%,much higher than in PLC（16.7%,P<0.05）;the lesion diameters in FNH foci was （4.8±0.8） cm,not statistically different compared to PLC foci[（5.1±0.8）cm,P>0.05];plain scan results showed that the proportion of low and equal signal in T1 in FNH foci were 84.6% and 15.4%,no significant difference compared with PLC foci（88.9% and 11.1%,P>0.05）;the proportion of high and equal signal in T2 in FNH foci were 88.5% and 11.5%,not statistically significantly different as compared with PLC foci（91.7% and 8.3%,respectively,P>0.05）;Tumor lesions often showed long T1 and long T2 signals in necrotic area in PLC foci,while FNH exhibited a central stellate structure and a signal of long T1 and long T2;the proportion of central scar and feeding arteries in FNH foci were radiologically 65.4% and 46.2%,much higher than 8.3% and 8.3% in PLC foci （P<0.05）;the proportion thrombus in portal vein and cirrhosis in FNH foci were 0.0% and 7.7%,much lower than 25.0% and 55.6% in PLC foci（P<0.05）;the proportion of fast-in and fast-out enhancement and swollen lymph nodes in FNH were 88.5% and 0.0%,not significant different as compared with PLC foci （86.1%and 11.1%,respectively,P>0.05）. Conclusion MRI can clearly distinguish PLC and FNH,which can help the diagnosis in clinical practice.

Key words: Primary liver cancer, Focal nodular hyperplasia, Magnetic resonance imaging, Enhanced features