A fast intensity based non-rigid 2D-3D registration using statistical shape models with application in radiotherapy
Christoph Bodensteiner, Cristina Darolti, Achim Schweikard · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2009
In this paper we present a novel fast method for the non-rigid registration of a few X-ray projections with CT data. The method involves non-parametric non-rigid registration techniques for the difficult 2D-3D case, combined with knowledge of probable deformations modeled as active shape models (ASMs). ASMs allow us to cope with as few as two projections by regularizing the registration process. The model is learned from deformations observed during respiration in a 4D-CT. This method can be applied in motion compensated radiation therapy to eliminate the need for fiducial implantation. We designed a fast C++ implementation for our method in order to make it practicable. Our tests on real 4D-CT data achieved registration times of 2-4 minutes using a desktop PC.