The aim of our study was to compare the signal-to-noise ratio (SNR) of liver parenchyma and the contrast-to-noise ratio (CNR) of hypervascular hepatocellular carcinoma (HCC) between conventional and SENSE dynamic MRI. Thirty-one consecutive patients who were strongly suspected of having HCC were enrolled in our study. The subjects consisted of 20 men and 11 women aged 52 years to 79 years (mean 66.8 years). Dynamic MRI was performed for each patient, with SENSE (SENSE MRI) and without SENSE (conventional MRI) on separate days. For the quantitative analysis, the liver SNR and the lesion-liver CNR of 25 hypervascular HCCs detected on both conventional and SENSE dynamic MRI were measured. The liver SNR of the arterial phase and the portal venous phase was 84.1+/-24.7 and 104.7+/-34.3, respectively, in conventional MRI, while it was 62.9+/-19.5 and 44.5+/-18.2, respectively, in SENSE MRI. SENSE MRI showed a statistically significantly lower SNR than conventional MRI (P<0.01). The lesion-liver CNR was 26.3+/-15.9 in conventional MRI and 39.0+/-19.6 in SENSE MRI. The lesion-liver CNR in SENSE MRI was significantly higher than in conventional MRI (P<0.01). The SNR in SENSE MRI is significantly lower than in conventional MRI, although the lesion CNR is significantly higher than in conventional MRI.