Three-Dimensional Imaging of the Experimental Spinal Cord Injury

serial light microscopy 765/494-7600 registration 765/494-7605 fax 2 SUMMARY The pathology of mammalian spinal cord injury (SCI) is usually defined as "central hemorrhagic necrosis", where variable amounts of the peripheral white matter is spared while the central grey matter deteriorates. This condition had traditionally made microinvestigation of the injury site in experimental animal models of SCI only possible through histology. Unfortunately, histological examination is confined to two dimensions, unless the spinal cord is three-dimensionally reconstructed. Three-dimensional (3-D) computer visualization is an ideal tool for the evaluation of the SCI and other soft tissue injuries where multiple pathological features may be embedded within each other. We have evaluated three different algorithms to three-dimensionally visualize spinal cord injuries. These tools are volumetric texturing, surface tiling, and isocontouring. To facilitate similar interdisciplinary efforts, we provide the computer science approaches that form the basis for this software. Our three-dimensional reconstruction techniques are not restricted to imaging alone. For the first time determination of the volume and surface area of spinal cord injuries or other structures embedded within them is possible using the reconstructed 3-D images themselves. During this evaluation we detected characteristic differences in the algorithms between two of the surface reconstruction methods that could influence quantitation. This was not observed, however, when these methods were compared to morphometric data generated by older two-dimensional (2-D) morphometric and geometric best-fitting approaches. We have also demonstrated the use of 3-D imaging technology to dynamically navigate into a three-dimensional spinal cord reconstruction and discuss the value of this and the other capabilities produced by these new methods.