ObjectiveTo investigate the significance of apparent diffusion coefficient (ADC value) for pretrea-tment prediction of short-term treatment effect in patients with hepatocellular carcinoma (HCC) who underwent transca-theter arterial chemoembolization (TACE). MethodsA total of twelve HCC patients with twenty-three HCC lesions who underwent TACE in our hospital from May. 2014 to May. 2015 were enrolled prospectively, to explore the difference between pre-and post-TACE in diameter of tumor, ADC value of HCC lesions, ADC value of liver parenchyma, and analyze the predictive significance of ADC value of HCC lesions for TACE in treatment of HCC. ResultsThere were no statistical difference between pre-and post-TACE in diameter of HCC lesions and ADC value of liver parenchyma (P=0.635, P=0.473), but the ADC value of HCC lesions was higher after TACE than pre-TACE (P=0.003). After TACE, the area of necrosis in HCC lesions was≥50% in 17 lesions (73.9%, good effect group), and <50% in 6 lesions (26.1%, poor effect group). Compared with poor effect group, ADC values of HCC lesions in good effect group were both higher before and after TACE (P<0.050). Area under ROC curve (AUC value) of ADC value in HCC lesions before TACE for predicting the effect of TACE was 0.690 (95% CI:0.510-0.879), with the sensitivity and specificity of 82.3% (95% CI:65.5%-93.2%) and 53.8% (95% CI:25.1%-80.8%) respectively, and the demarcation point for good effect and poor effect was 1.24×103 mm2/s. ConclusionThis preliminary study demonstrates that the ADC value of HCC lesions before TACE may be a useful indicator to predict early response of TACE in treatment of HCC.