Enhancement pattern of small hepatocellular carcinoma (HCC) at contrast-enhanced US (CEUS), MDCT, and MRI: intermodality agreement and comparison of diagnostic sensitivity between 2005 and 2010 American Association for the Study of Liver Diseases (AASLD) guidelines.

OBJECTIVE: To evaluate agreement between contrast-enhanced ultrasound (CEUS), multi-detector row computed tomography (MDCT) and magnetic resonance imaging (MRI) for the assessment of typical and atypical enhancement patterns of small hepatocellular carcinoma (HCC); and to compare diagnostic sensitivity of 2005 and 2010 American Association for the Study of Liver Diseases (AASLD) guidelines.

MATERIALS AND METHODS: Between January 2008 and December 2009, we included cirrhotic patients with newly diagnosed 10-20 mm HCC imaged at two contrast-enhanced imaging techniques among CEUS, MDCT, and MRI. Dynamic studies were reviewed by two radiologists to assess enhancement pattern. Percentage of cases with concordant findings and Cohen coefficient (k) were calculated. McNemar's test was used to compare sensitivity between 2005 and 2010 AASLD guidelines.

RESULTS: There were 91 patients (69 M; 22 F; mean age, 68 years) with 96 HCCs, studied with a combination of CEUS and MDCT (n=59), CEUS and MRI (n=26), or MDCT and MRI (n=11). Intermodality agreement for assessment of tumor enhancement pattern was 67% (k=0.294, P=0.001). Typical enhancement pattern was detected coincidentally at two imaging modalities in 50 (52%) HCCs. Sensitivity for the diagnosis of HCC increased significantly using the 2010 AASLD (81/96 (84%) vs. 50/96 (52%), P<0.001).

CONCLUSIONS: Agreement between two imaging modalities for the detection of typical tumor enhancement pattern was reached in 52% of cases. The 2010 AASLD guidelines significantly increased the sensitivity for the diagnosis of HCC.