Objective To analyze the MR manifestations of the focal nodular hyperplasia (FNH)in liver and observe the MRI changes after 30-36 months.Methods 12 (14 lesions)of the 13 patients (1 5 lesions)were firstly diagnosed as FNH by MRI with plain scan and dynamic Gd-DTPA enhancement,and then were confirmed by the follow-up survey with similar MRI after 30 - 36 months.The last one patient was also scanned with Gd-EOB-DTPA enhancement but with similar plain scans.The size,signal,en-hancement patterns of the lesions were analyzed and compared with those in the follow-up survey.Results Typical MR manifesta-tions were found in 93.33%(14/1 5)of the lesions with hypo-or iso-intensity on T1 WI,hyper-or iso-intensity on T2 WI,marked en-hancement in arterial phase and attenuation but still equal to or higher than normal liver parenchyma in portal and delayed phases af-ter Gd-DTPA administration.In addition,the central scar showed hypointensity on T1 WI,hyperintensity on T2 WI,and enhance-ment in delayed phase.The enhanced small vessels inside lesions and the pesudocapsule enhancement could be seen in delayed phase. The only one lesion with Gd-EOB-DTPA enhancement showed marked enhancement in arterial and portal phases,and slight hyperin-tensity in hepatocellular phase with hypo-intense central scar in any phases.As for the only one lesion with atypical manifestation,it showed isointensity on T1 WI,slightly hyperintensity on T2 WI,nonenhancement in arterial phase,slightly enhancement in portal phase,and small vascular enhancement inside the lesion in delayed phase.After the follow-up survey of 30-36 months 92.86%(13/14)lesions did not change,however one lesion (10mm)disappeared.Conclusion Typical FNH shows similar MRI characteristics, iso-intense or slightly hypo-intense signal on T1 WI,iso-intense or slightly hyper-intense signal on T2 WI,marked enhancement in ar-terial phase,the central scar enhancement and the inside small vascular enhancement of lesions in delayed phase.It is valuable in dif-ferential diagnosis.

Objective To evaluate the application of 1H-MRS in chronic liver diseases related with hepatitis B, and to investigate the method of eliminating breathing influence to proton MR spectroscopy (1H-MRS) on liver. Methods Liver spectroscopy of 46 subjects were obtained by single-voxel PRESS sequence with respiratory gating with GE 1.5T scanner. The subjects were divided into 4 groups: the normal male group (10 cases), the normal female group (10 cases), the male hepatitis B cirrhosis group (14 cases) and the male liver cancer after hepatitis B group (12 cases) according to clinical data, MR manifestations and pathologic findings. Glutamine and glutamate complex (Glx) peak height served as a reference standard to judge the choline (Cho) peak height. The differences of Cho peak height of each group were compared. Results The peaks of Cho were lower than those of Glx in normal male group. The peaks of Cho were higher than those of Glx in 8 women of normal female group. The peaks of Cho were higher than those of Glx in 11 patients of the male hepatitis B cirrhosis group. The peaks of Cho were higher than those of Glx in 10 patients of the male liver cancer after hepatitis B group. The differences of Cho peak were statistically significant between normal male group and normal female group, the male hepatitis B cirrhosis group and the normal male group, the male liver cancer after hepatitis B group and the normal male group. Conclusion The peaks of Cho in normal males are lower than those of Glx. The peaks of Cho in the majority of normal females are higher than those of Glx. The peaks of Cho increase in male hepatitis B cirrhosis and liver cancer after hepatitis B. Respiratory gating can effectively eliminate the impact of breathing movement on proton MR spectroscopy of liver.