A single camera roentgen stereophotogrammetry method for static displacement analysis

A new method to quantify motion or deformation of bony structures has been developed, since quantification is often difficult due to overlaying tissue , and the currently used roentgen stereophotogrammetry method requires sign ificant investment. In our method, a single stationary roentgen source is u sed, as opposed to the usual two, which, in combination with a fixed radiog ram cassette holder, forms a camera with constant interior orientation. By rotating the experimental object, it is possible to achieve a sufficient an gle between the various viewing directions, enabling photogrammetric calcul ations. The photogrammetric procedure was performed on digitised radiograms and involved template matching to increase accuracy. Co-ordinates of spher ical markers in the head of a bird (Rhea americana), were calculated with a n accuracy of 0.12 mm. When these co-ordinates were used in a deformation a nalysis, relocations of about 0.5 mm could be accurately determined. (C) 20 00 Elsevier Science Ltd. All rights reserved.