The detection of region of interest(ROI) in medical images has played a very important role in computer aided diagnosis. Because liver-focus organs have the characteristics of weak textural and small intensity differences with their neighborhood, a novel algorithm of extracting abnormal regions in liver CT images has been proposed in this paper, which uses visual attention model. Firstly, a set of statistical features related to liver textures and some salient factors based on directional fractals are selected. Then, an overall saliency map is composed from several sub-salient maps of feature components. Finally, the regions with liver focus are located by labeling the saliency map. Experiments show that the locations of liver focus regions could be found using the proposed method accurately and using saliency maps is an effective way of extracting ROI in medical images.