AIM We evaluated the ability to detect and diagnose small hepatocellar carcimoma (HCC) with the fat-saturation (fatsat) MR technique. MATERIALS and METHODS 22 HCCs smaller than 30mm were studied in consecutive series. Imagings were obtained using a 1.5T MR imager (Signa General Electric Co.) with spin echo pulse sequences (TR/TE:500/11;2000/30/80). T1WIs were obtained with and without fatsat. The detectability and the pattern of signal intensity relative to the liver parenchyma in each lesion were evaluated with all pulse sequences. On detectability and diagnostic capability for HCC, fat-saturated T1WI (T1FSWI) was compared with conventinal images by five experienced physicians using ROC analysis. RESULTS HCCs were detected most in number of lesions on TIFSWI in all pulse sequences. ROC analysis revealed a greater degree of confidence with T1FSWI than with T1WI on detectability and diagnostic capability for HCC. CONCLUSION It is suggested that the fatsat techenique may greatly contribute to the early diagnosis of HCC by MR imaging.