Image processing experiments for computer-based three-dimensional reconstruction of neurones from electron micrographs from serial ultrathin sections.

Abstract

This study examined an image processing technique that uses a computer to reconstruct a three-dimensional image of neurones from electron micrographs of serial ultrathin sections. The major problems involved were: (a) a distortion of features in electron micrographs; (b) a significant change of cross-section features of neurones in electron micrographs of neighbouring sections; and (c) disagreement between the electron microscopic section face and the coordinate plane desired for the reconstruction. Electron micrographs of a retinal bipolar cell stained with a biotinylated tracer were used. We corrected the distortion of features by means of a warp, a widely used algorithm in morphing image processing. The change of features between neighbouring electron micrographs was minimized by filling the gaps with an interpolated image produced by a dissolve, another algorithm in morphing, as well as the warp. The distortion of the three-dimensional reconstructed image made by piling up features was corrected by making the image with a wire frame model. Furthermore, in order to estimate a closed contour of features, an active contour model, Snakes, was applied to the electron microscope features. Snakes successfully detected the contour of the target feature, but in some electron microscope images broke into the target feature.