Toward Consistently Behaving Deformable Models For Improved Automation In Image Segmentation

Deformable models are a powerful approach to medical image segmentation. However, currently the behavior of a deformable model is highly dependent on its initialization and parameter settings. This is an obstacle to robust automatic or near-automatic segmentation. A generic approach to reducing this dependency is introduced in the present chapter based on topographic distance transforms from manually or automatically placed markers. This approach utilizes object and background differentiation through watershed theories. The implementation is based on efficient numerical methods such as the Fast Marching method and non-iterative reconstruction-by-erosion. Further extension into a multi-region coupled segmentation approach is discussed. Validation experiments are presented to demonstrate the capabilities of this approach. A preliminary application in pediatric dosimetry research is described. It is believed that the more consistent behavior will enable a higher degree of automation for segmentation employing deformable models and is particularly suited for applications that involve segmentation-based construction of organ models from image databases, especially in situations where the markers can be placed automatically based on a priori knowledge.