1Department of Anatomy, Institute of Neurobiology, Jiangsu Province Key Laboratory of Neural Regeneration, Medical School of Nantong University, Nantong  226001, Jiangsu Province, China

2Laboratory of Image Engineering, Medical School of Nantong University, Nantong  226001, Jiangsu Province, China

Guangming Lü☆, Ph.D., Associated professor, Department of Human Anatomy, Medical School of Nantong University, Nantong 226001, Jiangsu province, China Guangming Lü and Huiqun Wu contributed equally to this article Supported by: Natural Science Research Plan for Jiangsu Colleges, No. 05KJB180105*;  Postgraduate Innovation Cultivating Project in Jiangsu Province, No. CX07s_035z* Lü GM, Wu HQ, Tang LM, Han X, Ji DF, Gu XS. Three-dimensional reconstruction of human spinal cord based on histological serial sections. Neural Regen Res 2008;3(7):697-700

Abstract

BACKGROUND: It is not possible to reconstruct the inner structure of the spinal cord, such as gray matter and spinal tracts, from the Visual Human Project database or CT and MRI databases, due to low image resolution and contrast in macrosection images.

OBJECTIVE: To explore a semi-automatic computerized three-dimensional (3D) reconstruction of human spinal cord based on histological serial sections, in order to solve issues such as low contrast.

DESIGN, TIME AND SETTING: An experimental study combining serial section techniques and 3D reconstruction, performed in the laboratory of Human Anatomy and Histoembryology at the Medical School of Nantong University during January to April 2008.

SETTING: Department of Anatomy, Institute of Neurobiology, Jiangsu Province Key Laboratory of Neural Regeneration, Laboratory of Image Engineering.

MATERIALS: A human lumbar spinal cord segment from fresh autopsy material of an adult male.

METHODS: After 4% paraformaldehyde fixation for three days, serial sections of the lumbar spinal cord were cut on a Leica cryostat and mounted on slides in sequence, with eight sections aligned separately on each slide. All sections were stained with Luxol Fast Blue to reveal myelin sheaths. After gradient dehydration and clearing, the stained slides were coverslipped. Sections were observed and images recorded under a light microscope using a digital camera. Six images were acquired at ×25 magnification and automatically stitched into a complete section image. After all serial images were obtained, 96 complete serial images of the human lumbar cord segment were automatically processed with “Curves”, “Autocontrast”, “ Gray scale 8 bit”, “Invert”, “Image resize to 50%” steps using Photoshop 7.0 software. All images were added in order into 3D-DOCTOR 4.0 software as a stack, where serial images were automatically realigned with neighboring images and semi-automatically segmented for white matter and gray matter. Finally, simple surface and volume reconstruction were completed on a personal computer. The reconstructed human lumbar spinal cord segment was interactively observed, cut, and measured.

MAIN OUTCOME MEASURES: The reconstructed human lumbar spinal cord segment.

RESULTS: Compared with serial images obtained from other image modalities, such as CT, MRI, and macrosections from The Visual Human Project database, the Luxol Fast Blue stained histological serial section images exhibited higher resolution and contrast between gray and white matter. Image processing and 3D reconstruction steps were semi-automatically performed with related software. The 3D reconstructed human lumbar cord segment were observed, cut, and measured on a PC.

CONCLUSION: A semi-automatically computerized method, based on histological serial sections, is an effective way to 3D-reconstruct the human spinal cord.

Key Words: Luxol Fast Blue; reconstruction; serial sections; surface; three-dimensional; visible human project; volume

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