A comparative study of the quantitative accuracy of three-dimensional reconstructions of spinal cord from serial histological sections.

We evaluated the accuracy of estimating the volume of biological soft tissues from their three-dimensional (3D) computer wireframe models, reconstructed from histological data sets obtained from guinea-pig spinal cords. We compared quantification from two methods of three-dimensional surface reconstruction to standard quantitative techniques, Cavalieri method employing planimetry and point counting and Geometric Best-Fitting. This involved measuring a group of spinal cord segments and test objects to evaluate the accuracy of our novel quantification approaches. Once a quantitative methodology was standardized there was no statistical difference in volume measurement of spinal segments between quantification methods. We found that our 3D surface reconstructions' ability to model precisely actual soft tissues provided an accurate volume quantification of complex anatomical structures as standard approaches of Cavalieri estimation and Geometric Best-Fitting. Additionally, 3D reconstruction quantitatively interrogates and three-dimensionally images spinal cord segments and obscured internal pathological features with approximately the same effort required for standard quantification alone.

Advances in three-dimensional reconstruction of the experimental spinal cord injury.

Three-dimensional (3D) computer reconstruction is an ideal tool for evaluating the centralized pathology of mammalian spinal cord injury (SCI) where multiple anatomical features are embedded within each other. Here, we evaluate three different reconstruction algorithms to three-dimensionally visualize SCIs. We also show for the first time, that determination of the volume and surface area of pathological features is possible using the reconstructed 3D images themselves. We compare these measurements to those calculated by older morphometric approaches. Finally, we demonstrate dynamic navigation into a 3D spinal cord reconstruction.

Two- and three-dimensional computer graphic evaluation of the subacute spinal cord injury.

We have evaluated three-week-old compression lesions of the rat spinal cord using two-dimensional and three-dimensional morphometry, reconstruction, and visualization techniques. We offer a new computer assisted method to determine the number and density of macrophages within the spinal lesion using the macrophage specific monoclonal label ED1. We also provide quantitative information on pathological cyst formation and cavitation. This technique does not require: (1) subjective identification of the cell type, (2) human interaction with the data during the phase of quantification, and (3) can be applied to any sampling paradigm based on immunocytochemical labeling. Using novel algorithms based on solutions to 'correspondence' and 'branching' problems inherent in cross-sectional histological data, we provide three-dimensional reconstructions and visualizations of the macrophagic lesions and cysts imbedded within it. Our three-dimensional surface reconstructions can be interrogated to determine volumes and surface areas of structures within the data set. Using these methods we have learned that macrophage numbers approach the maximum density possible for such isodiametric cells (approximately 12 microm diameter) in the central lesion ranging from 4000-7000 cells per mm2 of lesion. At the time point studied, macrophage numbers would have peaked following the initial insult, and would not be expected to decline for several months. While the density of macrophages is highest in the region of most tissue damage, we show that the central regions of cavitated and cystic spinal parenchyma is not. We discuss how this density of cells may effect the secondary pathological responses of the spinal cord to injury.