[vtkusers] Precision of 3D measurements

[Boettcher, Dr. Peter]

When reconstructing bones out of CT data the in-plane resolution of the images is most of the time much better than the out-of plane resolution. Therefore one could argue that every 3D-measurement made on a 3D-opbject could not be "better" than the slice thickness of the original CT images. 

I do not believe this is true - but I have no arguments to defend my feeling.

The problem I am referring to is the following;
We did axial CT scans on canine elbows. Then we did 3D-measurements (in millimetre) on those 3D-reconstructed bones. The slice thickness used was 1mm and the increment 0.5mm. We expressed the measurements at 0.01mm precision.

Do you support this approach or what precision do you think is appropriate?

Regards, Peter.

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Peter Böttcher, Dr med vet, DipECVS
European Veterinary Specialist in Surgery
Fachtierarzt für Kleintierchirurgie 
Klinik für Kleintiere 
Universität Leipzig 
An den Tierkliniken 23
D-04103 Leipzig (Germany)
Tel: +49-341-9738700
Fax: +49-341-9738799
email: boettcher at kleintierklinik.uni-leipzig.de