Chemoembolization follow-up of hepatocellular carcinoma with diffusion-weighted MR imaging

PurposeTo assess the treatment response of hepatocellular carcinoma (HCC) after transarterial chemoembolization with diffusion weighted magnetic resonance (MR) imaging with a 1.5 T system.Materials and methodsThirty patients with 30 HCC focal lesions were prospectively evaluated for early treatment response after transarterial chemoembolization using dynamic contrast enhanced MRI and diffusion weighted MRI before and after the procedure. Diameter of arterially enhancing portions and apparent diffusion coefficient (ADC) values of lesions were recorded. The significance of differences between ADC values of completely responding and partially responding lesions was calculated.ResultsTumor ADC value increased from 1.2 + 0.1 × 103 mm2/s to 1.49 + 0.3 × 103 mm2/s after treatment (p < 0.001). There was a significant positive correlation between the percent change in the mean ADC and the percent change in the diameter of the enhancing tumor tissue after chemoembolization. The best predictive cutoff value for differentiation between complete and partial response was 24% change in the mean ADC.ConclusionResponding HCC lesions exhibited decreases in arterial enhancement and increases in ADC values. Percent change in the mean ADC values was predictive of response to chemoembolization.