Intravoxel Incoherent Motion Diffusion-Weighted MR Imaging can Differentiate between Residual or Recurrent Hepatocellular Carcinoma and Inflammatory Reaction Zone: A Single-Center Study

Abstract

Introduction The aim of this study was to explore the application of IVIM-DWI (intravoxel incoherent motion diffusion-weighted imaging) MRI (magnetic resonance imaging) in the evaluation of abnormal enhancement of the margin of hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA). Materials and Methods We performed a routine IVIM-DWI imaging review of patients who had been diagnosed with HCC and had received RFA in the past four years. We made quantitative comparisons of D, D*, and f in different tissues and lesions, and used one-way analysis of variance to compare quantitative data and an ROC (receiver operating characteristic) curve to analyze the diagnostic efficacy of the data. Results A total of 79 patients met the study’s criteria. The consistency of the measured values of the three surveyors was very good (ICC > 0.90). The D of recurrent HCC and the inflammatory reaction zone was (0.65 ± 0.16) × 10−3 mm2/s and (0.87 ± 0.05) × 10−3 mm2/s, respectively. The D* of recurrent HCC and the inflammatory reaction zone was (31.34 ± 11.54) × 10−3 mm2/s and (41.37 ± 5.11) × 10−3 mm2/s, respectively. The f of recurrent HCC and the inflammatory reaction zone was (18.16 ± 5.82)% and (24.21 ± 3.69)%, respectively. The differences in IVIM-DWI parameters between the two groups were all statistically significant (P < 0.001). Discussion Our research indicated that the D of recurrent HCC was lower than that of the inflammatory reaction zone. The optimal cutoff value can differentiate between these two types of lesions. Our research revealed a statistically significant difference in D* between recurrent HCC and the inflammatory reaction zone. The ROC curve shows that this optimal cutoff value has high diagnostic efficiency. The f is higher in hepatic parenchyma and inflammatory reaction zones than in other tissues. Therefore, f may help distinguish the inflammatory reaction zone from recurrent HCC. Conclusion IVIM-DWI is valuable for differentiating between regions of recurrent HCC and the inflammatory reaction zone in post-RFA tumors. In terms of diagnostic performance, D outperformed D* and f.