A novel colonwall flattening model for computed tomographic colonography: Method and validation

Computed tomographic colonography (CTC) has been developed for diagnosis of colon cancer. Flattening the three-dimensional (3D) colonwall into twodimensional (2D) image is believed to bemuch effective for providing supplementary information to the endoscopic views and further facilitating colon registration, taniae coli (TC) detection, and haustral folds segmentation. Though the previously-used conformal mapping-based flattening methods can preserve the angle, it has limitations in providing accurate information of the 3D inner colon wall due to the lack of undulating topography. In this paper, we present a novel colon wall flattening method based on a 2.5D approach. Coupling with the conformal flattening model, the new approach builds an elevation distance map to depict the neighborhood characteristics of the inner colon wall.We validated the new method via two CTC applicationsTC detection and haustral fold segmentation. Experimental results demonstrated the effectiveness of our model for CTC studies.