Purpose: To compare the diagnostic value of apparent diffusion coefficient (ADC) and intravoxel incoherent motion metrics in discriminating histologic grades of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV) infection.
Methods: 117 chronic HBV patients with 120 pathologically confirmed HCCs after surgical resection or liver transplantation were enrolled in this retrospective study. Diffusion-weighted imaging was performed using eleven b values (0-1500 s/mm^{2}) and two b values (0, 800 s/mm^{2}) successively on a 3.0 T system. ADC_{0, 800}, ADC_{total}, diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) were calculated. The parameters of three histologically differentiated subtypes were investigated using Kruskal-Wallis test, Spearman rank correlation, and receiver-operating characteristic analysis. Interobserver agreement was assessed using the intraclass correlation coefficient.
Results: There was excellent agreement for ADC_{total}/D/f, good agreement for ADC_{0,800}, and moderate agreement for D*. ADC_{total}, ADC_{0, 800,}D, and f were significantly different for well, moderately, and poorly differentiated HCCs (P < 0.001), and they were all inversely correlated with histologic grades: r = – 0.633, – 0.394, – 0.435, and – 0.358, respectively (P < 0.001). ADC_{total} demonstrated higher performance than ADC_{0,800} in diagnosing both well and poorly differentiated HCCs (P < 0.001 and P = 0.04, respectively). ADC_{total} showed higher performance than D and f in diagnosing well differentiated HCCs (P < 0.001) and similar performance in diagnosing poorly differentiated HCCs (P = 0.06 and 0.13, respectively).
Conclusions: ADC_{total} showed better diagnostic performance than ADC_{0,800}, D, and f to discriminate histologic grades of HCC.
【저자키워드】 Hepatocellular carcinoma, Intravoxel incoherent motion, Diffusion-weighted imaging, Apparent diffusion coefficient, Histologic grade,