3D Microscopic Anatomy Using Whole Slide Imaging (WSI)
Y Yagi, AR Sohani, M Mino-Kenudson, JR Gilbertson. Harvard Medical School, Boston, MA
Background: In the past, most 3D imaging in Pathology was done from a single slide using multiple focal planes (confocal microscopy or cytology) or through volume rendering of large, macro structures on multiple physical sections. However, WSI technologies and rendering software have now improved to the point that 3D reconstruction of large structure at microscopic scale from hundreds of serial sections is possible. The challenges in this approach include section registration, quality of tissue, effects of tissue processing and sectioning, and the huge amount of data that can be generated.
Design: Specimens included lymph node, pancreas and mouse embryo. 66-100 serial sections were cut manually or by an automated sectioning machine (AS-200, KURABO INDUSTRIES LTD. Japan) from formalin-fixed paraffin-embedded blocks and stained with H&E. Serial sections were scanned at 0.33/pixel using a Mirax Scan device (3DHISTECH Ltd, Carl Zeiss Microimaging GmbH). 3D reconstruction was done using Mirax software. WSI were aligned to produce a 66-100 section 3D stack that could be subsampled, sectioned in various planes, freely rotated to expose 3D relationships in tissue. Spacing between scanned sections was varied dynamically during the analysis to explore specific features.
Results: Morphologic features were often enhanced upon 3D reconstruction, although the relatively low resolution of the 3D model precluded extensive analysis of cellular interactions. The reconstruction process was made more difficult by tissue processing effects such as wrinkle, stretch, bubble, variable thickness across the tissue section. Figure 1 and 2 show full and cut models of mouse embryo and pancreas.
Conclusions: 3D reconstruction from multiple serial WSI sections can be used to generate impressive views of tissue. In the future this technique could be an important aspect of pathology analysis. However, we need to overcome many challenges to make this are routine process.
Wednesday, March 11, 2009 9:30 AM
Poster Session V # 216, Wednesday Morning