Mitosis Detection

Ever wonder how an egg turns into an embryo? Well, it turns out no one really knows exactly how or why this happens, and without knowing this we cannot answer very important questions like how birth defects occur or how we can prevent them. People in the Embryo Biomechanics Group, at the University of Waterloo, study the process of embryogenesis using concepts from civil engineering, biomechanics, biology, image processing etc. An important finding by this group is that frequency and direction of cell division can cause internal forces that drive embryo epithelia deformation.

As part of this group I helped develop a computer vision algorithm for detecting cell divisions (mitosis) on live time lapse images of embryonic tissue. We used axolotl as our specimen, and a custom build robotic microscope system obtained images like the following:

Embryo Tissue 1 Embryo Tissue 2 Embryo Tissue 3

In these time lapse images a single mitosis and its direction can be identified as follows:

Single Mitosis

There were no automatic means of detecting mitosis in images without prior chemical treatments of the tissue. Since our group observes the natural development of live tissue, the existing methods were unsuitable. So I came up with two algorithms, one based on motion study and the other based on intensity study to determine the occurance and direction of cell division. The motion based algorithm produced accuracies of 65% and the intensity based algorithm produced accuracies of 75%. If high resolution images are used the intensity based algorithm can produce accuracies of 90%.

References

[1] P. Siva, G. W. Brodland and D. A. Clausi (2009)"Detection of mitoses in embryonic epithelia using motion field analysis", Computer Methods in Biomechanics and Biomedical Engineering, 12:2, 151-163.

[2] P. Siva, G. W. Brodland and D. A. Clausi "Automated Detection of Mitosis in Embryonic Tissues", 2007 Fourth Canadian Conference on Computer and Robot Vision, Montreal, pp.97-104.

[3] P. Siva, (2007)"Quantifying the frequency and orientation of mitoses in embryonic epithelia", MASc Thesis, University of Waterloo.