A systematic study of the effect of measurement parameters on determination of osteocyte lacunar properties using laboratory X-ray micro-computed tomography.

Accurate 3D characterization of osteocyte lacunae is important when investigating the role of osteocytes under various physiological and pathological conditions but remains a challenge. With the continued development of laboratory X-ray micro-computed tomography, an increasing number of studies employ these techniques beyond traditional bone morphometry to quantify osteocyte lacunae. However, there is a lack of knowledge on the effect of measurement parameters on the image quality and resolution and in turn the osteocyte lacunar quantification. Herein, we have examined the interplay between scan parameters and the resultant lacunar quantification in terms of lacunar size, shape, and density by comparison with a synchrotron benchmark dataset. We summarize our conclusions in a guide for use of μ-CT for osteocyte lacunar quantification: (1) Identification of the measurement requirements to address the research questions. (2) Collection and preparation of suitable sample(s) that fulfills these requirements. (3) Experimental considerations including determination of the required voxel size, in turn dictating the maximum FOV and by extension the maximum size of the sample(s). The experimental parameters chosen should ensure optimal image contrast, sufficient signal to noise, angular sampling etc. Usually, it is advisable to measure as well as possible within the limits of time, budget, data storage and analysis capabilities. (4) Data analysis and reporting of the results, including visual examination of the data at multiple steps in the analysis, to ensure correct feature identification and suitable reporting approaches. (5) Cross study comparisons, which may be unsuitable if the experimental conditions and analysis strategies are not comparable.