Effect of specimen size on microCT cortical tissue measurements

Aims The increasing interest in cortical bone strenght [1,2] led up to the investigation of the cortical tissue through X-ray microcomputed tomography (microCT). In the past histology has been the gold standard for the morphometric examination of bone specimens but this new method permits the non-destructive analyses of specimens in a faster way preserving the integrity of the samples [3] and the calculation of the morphometric parameters over the whole sample’s volume. The accuracy of microCT bone measurements can be influenced by a segmentation method that, through a threshold value, separates “bone” from “non bone” in the reconstructed grayscale datasets. In order to validate the characterization of human cortical bone microarchitecture using micro-CT, cortical measures were compared with those obtained through histological examination [4,5]. Since studies often compare samples with a range of different sizes, the accurate measurement in specimens of unequal size is important. The aim of this work was to compare microtomographic and histological analyses of cortical bone specimens of two different sizes, and to investigate how cortical measures are affected by errors when a different threshold value is applied.