Ultrasound, a new tool for surface matching in computer-navigated surgery.
OBJECTIVE
The object of this study was to investigate the feasibility of generating a bone surface from data provided by an ultrasound examination and to match this surface with the previous computed tomography (CT) scan.


METHODS
From a CT data set of a training model of the pelvis, a three-dimensional surface was extracted by global thresholding-based segmentation. The same model was placed in a water basin, and ultrasound images were taken with a guided ultrasound transducer. The three-dimensional surface was generated from the ultrasound data set, and the two surfaces were matched in a semiautomatic mode.


RESULTS
With special segmentation methods, a surface could be extracted automatically from the CT and the ultrasound data set. From these segmented ultrasound slices, a volume data set of the model was generated. After approximate initial matching, the local matching process was completed automatically.


CONCLUSIONS
One of the limitations in computer-assisted surgery is the complicated matching process. Using special algorithms, a surface was extracted from the data set of an ultrasound examination and matched in a semiautomatic mode with the surface of a CT data set, facilitating the matching process.
Liener
Ulrich C
UC
Department of Trauma and Reconstructive Surgery, University of Ulm, Ulm, Germany.
Krivonos
Oleg
O
Männer
Reinhard
R
Hesser
Jürgen
J
Kinzl
Lothar
L
Gebhard
Florian
F
D000465:Algorithms; D005240:Feasibility Studies; D006801:Humans; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed / Q000379:methods; D014463:Ultrasonography / Q000191:economics / Q000379:methods*