Role of Dynamic Contrast-Enhanced MRI in Follow-Up of Patients with Hepatocellular Carcinoma after Trans-Catheter Arterial Chemoembolization

Background: MRI with its functional imaging techniques including dynamic study is a powerful tool in detection of tumor viability and complications after trans-catheter arterial chemoembolization of hepatocellular carcinoma. This study found that dynamic study is the gold standard in detection of the recurrent lesions. Well defined nodular enhancement, thick irregular marginal enhancement or gross enlargement of the lesion with arterial phase enhancement and contrast wash out were considered positive for malignancy, while ill-defined persistent enhancement or well defined rim marginal enhancement are considered as benign post interventional changes.Objective: The purpose of this study is to emphasis the role of dynamic contrast enhanced MRI in follow-up of patients with hepatocellular carcinoma after trans-catheter arterial chemoembolization.Patients and Methods: Twenty five patients with HCC underwent chemoembolization were included in this study. Follow-up by dynamic MRI and diffusion imaging was done at different time intervals. We classified the patients into resolved “benign” group and unresolved malignant group. We assessed and classified our patients according to morphological changes (size and signal intensity at T1, T2 and diffusion weighted images), quantitative diffusion analysis (ADC measurement), enhancement pattern in the dynamic study and the presence of complications.Results: Dynamic MRI study 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 an overall agreement of 94%.Conclusion: MRI is a powerful tool in detection of tumor viability and complications after trans-catheter arterial chemoembolization of hepatocellular carcinoma. Imaging protocol should include dynamic study combined with diffusion imaging with post processing of the images to obtain subtracted images, color mapping and ADC measurements for better tissue characterization and should be performed at regular time intervals.