# Abstract for ijaz_tr635

Cambridge University Engineering Department Technical Report CUED/F-INFENG/TR 635

OPTIMISATION STRATEGIES FOR ULTRASOUND VOLUME REGISTRATION

Umer Zeeshan Ijaz, Richard W. Prager, Andrew H. Gee and Graham M. Treece

August 2009

This paper considers registration of 3D ultrasound volumes. One way to acquire 3D data is to use a mechanically-swept 3D probe. However, the usefulness of these probes is restricted by their limited field of view. While this problem can be overcome by attaching a position sensor to the probe, an external position sensor can be an inconvenience in a clinical setting and does not align the volumes correctly when there is tissue displacement or deformation. The objective of this paper is to replace the 6 degree of freedom (DOF) sensor with a combination of 3 DOF image registration and an integrated intertial sensor for measuring orientation. We examine a range of optimisation algorithms and similarity measures for registration and compare them in \emph{in vitro} and \emph{in vivo} experiments. We register based on multiple reslice images rather than a whole voxel array. In this paper, we use a large number of reslices for improved reliability at the expense of computational speed. We have found that the Levenberg-Marquardt method is very fast but is not guaranteed to give the correct solution all the time. We conclude that normalised mutual information used in the Nelder-Mead simplex algorithm is potentially suitable for the registration task with an average execution time of around five minutes, in the majority of cases, with two restarts in a C++ implementation on a 3.0 GHz Intel Core 2 Duo CPU machine.

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