Comparison of image quality between a medical and an industrial ct scanner for use in non-destructive testing of tree-ring widths in an oak (Quercus robur) historical sculpture of Madonna
The aim of this paper was to compare the tree-ring width measurement results obtained using standard medical CT scanner Light Speed VCT 64 with the results obtained from industrial CT scanner GE phoenix v|tome|x 240 during dendrochronological dating of a historical wooden sculpture. The examined object was a polychrome wooden sculpture of Madonna, which was of historical value – that is why equipment enabling non-destructive measurement of tree-ring width for dendrochronological dating had to be used. The sculpture was made of ring porous English oak wood (Quercus robur), which is very easy to measure. There are also standard chronologies available for this material for the area of the Czech Republic to be used for absolute dendrochronological dating. During the first stage of the research, an available CT scanner designed for medical examination of human tissue was used; then the object was measured again using an industrial CT scanner where better results could be expected thanks to higher image resolution. This paper compares the quality of images from both scanners and the results of tree-ring width measurement from the output of the two CT scanners. The re-sults successfully document the possibility of obtaining images of sufficient quality to measure the grow ring widths of oak wood using computed tomography, proving that wooden objects can be subject to dendrochronological dating even if strict non-destructivity is required.