Amide Proton Transfer-Weighted MRI For Predicting Histological Grade Of Hepatocellular Carcinoma

Purpose:To prospectively evaluate the feasibility and capability of amide proton transfer(APT)MRI in predicting the histological grade of hepatocellular carcinoma(HCC),compared with diffusion-weighted imaging(DWI).Materials and Methods:Between May 2017 and April 2018,32 consecutive patients with pathologically confirmed HCC were enrolled,including 19 high-grade HCCs and 13 low-grade HCCs,who underwent APT MRI and DWI with 2 values(0,1000 s/mm2)on a 3.0-T MRI scanner.The APT and DWI images were post-processed in external software,respectively.Two observers drew regions of interest independently by referring to the axial T2-weighted imaging.APTw values and apparent diffusion coefficient(ADC)values were acquired,respectively.Inter-and intra-observer agreements were assessed by using the intraclass correlation coefficients.The independent sample t test was used to compare the difference of APTw and ADC value between the high-and low-grade HCC tumor parenchyma.The receiver operating characteristic curve was used to analyze the efficacy of APTw and ADC value to distinguish high-and low-grade HCCs.Spearman correlation analysis was used to assess the relationship between APTw value,ADC value,and HCC histological grade.Results:The inter-and intra-observer agreements showed excellent,with ICCs of 0.856 and 0.750 for APTw,0.936 and 0.800 for ADC,respectively.Significant differences were found between the APTw or ADC values for the high-and low-grade HCC groups(P=.034 and.010).The ROC analyses demonstrated that the APTw and ADC values had good diagnostic performance in differentiating the high-grade HCC from the low-grade HCC,with areas under the curve of 0.814 and 0.745.Moderate correlations were found between APTw and histological grades(r=0.534;P=.002),as well as ADC values and histological grades(r=-0.417;P=.018).Conclusion:The APTw imaging is a valuable imaging biomarker,which has certain value for the differential diagnosis of high-and low-grade HCC s.Combined with DWI,it is more helpful to accurately and comprehensively reflect the characteristics of HCC.