**2. Overview of the proposed method**

Our method is composed of seven steps: (1) read the CT images; (2) extract the liver region using a well-established liver region segmentation program [8]; (3) smooth out the noise from the CT images; (4) enhance the CT image contrast by using probability density functions (PDFs) estimated from the training data; (5) remove vessels by applying Maximum likelihood method; (6) detect tumor candidates by employing the EM/MPM algorithm; and (7) detect and segment the tumor regions by using a shape filter.

Fig. 1. The flowchart of our proposed method for tumor detections
