To assess the value of diffusion kurtosis imaging (DKI) in distinguishing hepatocellular carcinoma (HCC) from other benign hepatic nodules.

According to the pathological results, 150 hepatic nodules of 112 patients from the First Affiliated Hospital of Sun Yat-sen University were divided into two groups: benign group (26 of focal nodular hyperplasia, 24 of hemangioma, 6 of hepatocellular adenoma) and malignant group (94 of HCC). Preoperative MRI examinations including DKI (b values: 0, 50, 200, 400, 800 and 2 000 s/mm²) were performed. Apparent diffusion coefficient (ADC) and DKI-derived parameters such as diffusivity values (D), kurtosis values (K) were analyzed by Logistic regression and receiver operating characteristic (ROC) curve to evaluate their efficacy for distinguishing HCC from benign hepatic nodules.

The median (interquartile range) values of ADC, D and K of malignant group were 1.172(0.389)×10^-3 mm²/s, 1.751(0.759)×10^-3 mm²/s, and 0.013(0.315), while those of benign group were 1.670(0.675)×10^-3 mm²/s, 2.510(1.186)×10^-3 mm²/s and 0.162(0.223), respectively. There were statistically significant differences in ADC, D and K between the two groups(all P<0.001). The area under the curve of ADC, D, and K to identify HCC and liver benign nodules were 0.815, 0.779, and 0.722, and the optimal cut-off values were 1.238×10^-3 mm²/s, 1.881×10^-3 mm²/s, 0.056, the sensitivity, specificity and accuracy were 87.5%, 59.6%, 76.7% (ADC) ; 83.9%, 62.8%, 76.0% (D); 75.0%, 60.6%, 70.0% (K), respectively.

DKI parameter values D, K and conventional DWI parameter value ADC can be used to distinguish HCC from focal nodular hyperplasia, hemangioma and hepatocellular adenoma. The sensitivity, specificity and accuracy of ADC are higher than D and K.