Role of Diffusion-Weighted MRI in Hepatocellular Carcinoma Patients Following Transarterial Chemoembolization (TACE)

Abstract

Background: Hepatocellular carcinoma is one of the commonest cancers all over the world with very high mortality rates. TACE is used to deliver chemotherapeutic agents locally to the tumor. Aim of the work: The purpose of this study was to evaluate the role of diffusion-weighted MRI and ADC value in comparison with dynamic MRI in the assessment of response and necrosis to treatment of hepatocellular carcinoma after transcatheter arterial chemoembolization. Patients and Methods: Precontrast T1, T2, STIR, respiratory triggered diffusion-weighted (b factor 20, 500 and 800 s/mm2) and dynamic contrast enhanced MR images obtained in 50 patients with HCC who underwent TACE. Diffusionweighted MR images, gadolinium-enhanced MR images after TACE were assigned confidence levels for postoperative HCC recurrence. Results: Dynamic MRI had a sensitivity of 90.5%, a specificity of 96.6%, a positive predictive value of 95 %, a negative predictive value of 93.3% and overall agreement of 94%. Compared to 95.83%, 69.23%, 74.19%, of 94.74% and 82% respectively of diffusion-weighted imaging. The difference between the malignant and negative groups' ADC variables were statistically significant (P value 0.006). The ROC curve showed that the area under the curve is C = 0.728 with SE = 0.075 and 95% CI from 0.582 to 0.874. Conclusion: Diffusion-weighted MR imaging has lower specificity compared to dynamic MRI with increased false positives. We suggest that the increase is due to intra-lesional hemorrhage or liquefactive necrosis causing diffusion restriction. Diffusion-weighted imaging may act as a supplementary sequence to compensate the dynamic MRI in patients who could not hold their breath adequately.