Magnetic susceptibility and R2*-based texture analysis for evaluating liver fibrosis in chronic liver disease

Purpose To explore potential feasibility of texture features in magnetic susceptibility and R2* maps for evaluating liver fibrosis. Methods Thirty-one patients (median age 46 years; 22 male) with chronic liver disease were prospectively recruited and underwent magnetic resonance imaging (MRI), blood tests, and liver biopsy. Susceptibility and R2* maps were obtained using a 3-dimensional volumetric interpolated breath-hold examination sequence with a 3T MRI scanner. Texture features, including histogram, gray-level co-occurrence matrix (GLCM), gray-level dependence matrix (GLDM), gray-level run length matrix (GLRLM), gray-level size zone matrix (GLSZM), and neighboring gray tone difference matrix (NGTDM) features, were extracted. Texture features and blood test results of non-significant (Ishak-F<3) and significant fibrosis patients (Ishak-F≥3) were compared, and correlations with Ishak-F stages were analyzed. Areas under the curve (AUCs) were calculated to determine the efficacy for evaluating liver fibrosis. Results Nine texture features of susceptibility maps and 19 features of R2* maps were significantly different between non-significant and significant fibrosis groups (all P<0.05). Large dependence high gray-level emphasis (LDHGLE) of GLDM and long run high gray-level emphasis (LRHGLE) of GLRLM in R2* maps showed significantly negative and good correlations with Ishak-F stages (r=-0.616, P<0.001; r=–0.637, P<0.001). Busyness (NGTDM) in susceptibility maps, LDHGLE (GLDM) and LRHGLE (GLRLM) in R2* maps yield the highest AUCs (AUC=0.786, P=0.007; AUC=0.807, P=0.004; AUC=0.819, P=0.003). Conclusion Texture characteristics of susceptibility and R2* maps revealed possible staging values for liver fibrosis. Susceptibility and R2*-based texture analysis may be a useful and noninvasive method for staging liver fibrosis.