TY - CHAP T1 - Liver segment approximation in CT data for surgical resection planning T2 - Medical Imaging 2004: Image Processing Y1 - 2004 AB - Surgical planning of liver tumor resections requires detailed three-dimensional (3D) understanding of the complex arrangement of vasculature, liver segments and tumors. Knowledge about location and sizes of liver segments is important for choosing an optimal surgical resection approach and predicting postoperative residual liver capacity. The aim of this work is to facilitate such surgical planning process by developing a robust method for portal vein tree segmentation. The work also investigates the impact of vessel segmentation on the approximation of liver segment volumes. For segment approximation, smaller portal vein branches are of importance. Small branches, however, are difficult to segment due to noise and partial volume effects. Our vessel segmentation is based on the original gray-values and on the result of a vessel enhancement filter. Validation of the developed portal vein segmentation method in computer generated phantoms shows that, compared to a conventional approach, more vessel branches can be segmented. Experiments with in vivo acquired liver CT data sets confirmed this result. The outcome of a Nearest Neighbor liver segment approximation method applied to phantom data demonstrates, that the proposed vessel segmentation approach translates into a more accurate segment partitioning. JF - Medical Imaging 2004: Image Processing PB - SPIE CY - Bellingham; WashingtonScheele, J., Anatomical and atypical liver resection (2001) Chirurg, 72 (2), pp. 113-124;Couinaud, C., (1957) Le Foie - Etudes Anatomiques et Chirurgicales, , Masson, Paris; Strunk, H., Stuckmann, G., Textor, J., Willinek, W., Limit N1 - ScopusID: 5644267870doi: 10.1117/12.535514 ER - TY - JOUR T1 - Virtual dissection and automated polyp detection of the colon based on spiral CT - Techniques and preliminary experience on a cadaveric phantom JF - EUROPEAN SURGERY - ACTA CHIRURGICA AUSTRIACA Y1 - 2002 AB - Background: CT colonography was found to be sensitive andspecific for detection of colonic polyps and colorectal cancer (CRC). Depending on the software used, CT colonography requires a certain amount of operator interaction, which limits it's widespread usage. The goal of this papers is to present two novel automated techniques for displaying CT colonography: virtual dissection and automated colonic polyp detection. Methods: Virtual dissection refers to a technique where the entire colon is virtually stretched and flattened thus simulating the view on the pathologist's table. Colonic folds show a 'global outward bulging of the contour', whereas colonic polyps exhibit the inverse ('local inward bulging'). This feature is used to map areas of 'local inward bulging' with colours on 3D reconstructions. A cadaveric phantom with 13 artificially inserted polyps was used for validation of both techniques. Results: On virtual dissection all 13 inserted polyps could be identified. They appeared either as bumps or as local broadening of colonic folds. In addition, the automated colonic polyp detection algorithm was able to tag all polyps. Only 10 min of operator interaction were necessary for both techniques. Conclusions: Virtual dissection overcomes the shortcomings of CT colonography, and automated colonic polyp detection establishes a roadmap of the polyps. VL - 34 SN - 1682-8631 IS - 2 N1 - ScopusID: 0037000327doi: 10.1046/j.1563-2563.2002.02018.x JO - EUR SURG-ACA ER - TY - CHAP T1 - Virtual dissection of the colon: technique and first experiments with artificial and cadaveric phantoms T2 - Medical Imaging 2002: Visualization, Image-Guided Procedures, and Display Y1 - 2002 AB - Virtual dissection refers to a display technique for polypdetection, where the colon is digitally straightened and then flattened using multirow detector Computed Tomograph (CT) images. As compared to virtual colonoscopy where polyps may be hidden from view behind the folds, the unravelled colon is more suitable for polyp detection, because the entire inner surface of the colon is displayed in a single view. The method was tested both on artificial and cadaveric phantoms. All polyps could be recognized on both phantoms. This technique for virtual dissection requires only a minimum of operator interaction. JF - Medical Imaging 2002: Visualization, Image-Guided Procedures, and Display PB - SPIE CY - Bellingham; Washington N1 - ScopusID: 0036061143doi: 10.1117/12.466982 ER -