Evaluating histologic differentiation of hepatitis B virus-related hepatocellular carcinoma using intravoxel incoherent motion and AFP levels alone and in combination

Purpose: To evaluate histologic differentiation of hepatitis B virus (HBV)-related hepatocellular carcinomas (HCCs) using apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM)-derived metrics and to compare findings with alpha-fetoprotein (AFP) levels alone and in combination. Materials and method: One hundred and six chronic HBV-related HCC patients who underwent IVIM diffusion-weighted magnetic resonance imaging with eleven b values were enrolled. Mean ADC, diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) values were determined for all detected lesions. The metrics and AFP levels of different histologically differentiated groups were compared. Spearman's rank correlation was used to assess the statistical dependence among the histologically differentiated HCCs. Receiver operating characteristic (ROC) analysis was performed to evaluate diagnostic performance of these metrics and AFP levels alone and in combination. Results: ADC, D, and f values and AFP levels were significantly different among well-, moderately, and poorly differentiated HCCs. The four metrics were significantly correlated with histologic differentiation. The area under the ROC curve (AUC-ROC) of ADC, D, f, and AFP for diagnosing well-differentiated HCCs was 0.903, 0.84, 0.782, and 0.806, respectively, and the AUC-ROC of above metrics for diagnosing poorly differentiated HCCs was 0.787, 0.726, 0.624, and 0.633, respectively. The combination of ADC and AFP provided an AUC-ROC of 0.945 for well-differentiated HCC. However, this did not provide better performance for diagnosing poorly differentiated HCC. Conclusion: ADC, IVIM metrics, and AFP levels may be useful for evaluating histologic differentiation of HBV-related HCCs, and the combination of ADC and AFP provides better diagnostic performance for well-differentiated HCC.