GENERATING A NORMALIZED GEOMETRIC LIVER MODEL USING WARPING

RATIONALE AND OBJECTIVES. Automated liver surface determination in abd ominal computed tomography scans, currently difficult to achieve, is o f interest to determine liver location and size for various medical ap plications, including radiation therapy treatment planning, surgical p lanning, and oncologic monitoring. The authors propose to facilitate a utomation by the addition of a priori shape information in the form of a liver model. METHODS. The normalized geometric liver model is gener ated by averaging outlines from a set of normal liver studies previous ly registered using thin-plate spline warping. The model consists of a n averaged liver surface, a set of anatomic landmarks, and a deformati on function. RESULTS. A liver model is presented and its ability to re present normal liver shapes is demonstrated. CONCLUSIONS. Liver surfac e warping provides a means of data normalization for model constructio n and a means of model deformation for representation of liver organ s hapes.