The development of an image-guided renal surgery system may aid tumor resection during partial nephrectomies. This system would require the registration of pre-operative kidney CT or MR scans to the physical kidney; however, the amount of non-rigid deformation occurring during surgery and whether it can be corrected for in an image-guided system is unknown. One possible source of non-rigid deformation is a change in pressure within the kidney: during surgery, clamping of the renal artery and vein results in a loss of perfusion, such that the subsequent cutting of the kidney and fluid outflow may cause a decrease in intrarenal pressure. In this work, we attempt to characterize the deformation due to cutting of the kidney and subsequent changes in intrarenal pressure. To accomplish this, we perfused a resected porcine kidney at a physiologically realistic pressure, clamped the renal vessels, and cut the kidney using a tracked scalpel. The resulting deformation was tracked in a CT scanner using 15-20 glass bead fiducials attached to the kidney surface. A modified form of Biot's consolidation model was used to simulate the deformation, and the accuracy was assessed by calculating the target registration error and image similarity.

Date Published: 13 March 2009
PDF: 9 pages
Proc. SPIE 7261, Medical Imaging 2009: Visualization, Image-Guided Procedures, and Modeling, 72613A (13 March 2009); doi: 10.1117/12.813091

Published in SPIE Proceedings Vol. 7261:
Medical Imaging 2009: Visualization, Image-Guided Procedures, and Modeling
Michael I. Miga; Kenneth H. Wong, Editor(s)