MEDICAL CAT-SCANNING - X-RAY ABSORPTION-COEFFICIENTS, CT-NUMBERS AND THEIR RELATION TO WOOD DENSITY

This paper describes how X-ray absorption coefficients and CT-number in medical CAT-scanning can be calculated for dry and wet wood. A comparison with earlier recorded data for dry wood showed that the deviation between calculated and measured CT-numbers was not significant. Linear regression showed that wood density could be measured with an accuracy of +/- 4 kg/m3. Wood having the same green density but containing different amounts of water have different absorption coefficients and CT-numbers. A linear relationship between CT-numbers and density of wood containing water was developed. Wood density could be measured with an accuracy of +/- 13.4 kg/m3.