Hypervascular hepatocellular carcinoma in the cirrhotic liver: Diffusion-weighted imaging versus superparamagnetic iron oxide-enhanced MRI

Purpose: The purpose of the study was to validate diffusion-weighted imaging (DWI) in the assessment of hypervascular hepatocellular carcinoma (HCC) compared with superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) in the cirrhotic liver. Material and Methods: Forty-six consecutive patients with 106 hypervascular focal lesions in the cirrhotic liver who underwent DWI using three b factors and gadopentetate dimeglumine-enhanced dynamic MRI followed by SPIO-enhanced MRI were enrolled. Two independent radiologists evaluated two separated image sets (SPIO set, dynamic MRI and SPIO-enhanced T2*-weighted images; DWI set, DWI and dynamic MRI) and assigned confidence levels for diagnosis of HCC using a five-point scale for each lesion. Area under the receiver operating characteristic curve (A _z) was calculated for each image set. Results: The A _z value of the DWI set was larger than the SPIO set by both readers (reader 1, 0.936 vs. 0.900, P=050; reader 2, 0.938 vs. 0.905, P=110). For the sensitivity (reader 1, 93.1% vs. 86.2%, P=146; reader 2, 95.4% vs. 88.5%, P=070) and specificity (reader 1, 89.5% vs. 73.7%, P=250; reader 2, 79.0% vs. 73.7%, P=1.000) of HCC diagnosis, DWI sets were superior to SPIO sets without statistically significant differences. Conclusion: For assessment of hypervascular HCC, DWI in combination with dynamic MRI provides comparable or slightly better information compared with the combination of dynamic and SPIO-enhanced MRI.