In order to evaluate the accuracy of preoperative segmental localization of hepatic mass lesions

68 cases were prospectively studied and evaluated by the correlation of magnetic resonance imaging （MRI） and surgical findings. Right

middle and left hepatic veins were seen in 100%

97% and 94% of the subjects respectively on MRI. The right and left portal veins were seen in 100% and 95.6% respectively. The accuracy in determining the segmental location of hepatic lesions was 89.7%. The accuracy could be increased to 91. 3% if the lesion was located at single segment whereas it was only 86. 4% when the lesion extended across several segments. It is possible to say that MRI is an important modality in the preoperative segmental localization of masses.