The inherent demand for unbiasedness for some stereological estimators imposes a demand of not only positional uniform randomness but also isotropic randomness, i.e. directional uniform randomness. In order to comply with isotropy, one must perform a random rotation of the object of interest before it is embedded and sectioned. This has the unfortunate side effect that all information about positioning within the object is lost for blocks and sections. For complex tissue, like the mammalian brain, this information is of utmost importance to ensure measurements are performed in the correct region and on the correct subset of cells. This paper introduces a newly developed 3D stereological probe, the Spatial Rotator, which utilizes the computational and graphical powers of modern stereological workstations to eliminate the need for initial rotation of the specimen. Instead, the requirement for isotropy is obeyed by randomizing the orientation of the virtual probe itself within the thick section. Overall, the benefit is that positional information is kept for any block and section of the specimen. As the Spatial Rotator is a 3D probe, data must be gathered from sections thicker than 25 micro meters to form a 3D image on which the probe is applied. All steps regarding data aquisition, data visualization and application of the probe are described in detail. Simulations verifying the theoretical properties of the probe have been performed and are described. Furthermore, results of applying the probe on real tissue sections are described and compared to previous measurement of the same tissue using published stereological probes.
Stereology and Image Analysis. Ecs10: Proceeding of the 10th European Conference of Iss, 2009
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Miriam Project Series (milan Research Centre for Industrial and Applied Mathematics)