1. 3D texture analysis for characterising the structure of cancellous bone Picture in the middle By: Rafael Aragon Supervisor: Murk Bottema

2. Project aim Find a method for quantifying textures to distinguish different health states of bone. Motivation – Monitor diseases – Prescribe medications – Life style choices – Discover underlying medical conditions

3. Biomedical side Bone health states – Living tissue – Remodels over time – Osteoblasts and Osteoclasts Related to hormones – Multiple hormones – Males and females affected

4. The rats Data was obtained from 30 Sprague-Dawley rats by micro CT scans. – Retrospective study – Scans were on the tibia bone. Scans taken on weeks 0, 2, 4, 8 and 12 – Balance of data collection vs radiation exposure

5. The rats 30 rats in total – there were 3 different experimental groups. – 10 rats were ‘sham rats’ – 10 rats were ‘ovx rats’ – 10 rats were ‘ovx + treament rats’ Treatment started in week 2

6. Surgery and hormones Ovariectomy is the surgical removal of ovaries Low oestrogen is correlated to sparse bones ‘Ovx rats’ had their cancellous bone greatly reduced by the end of the experiment

7. What is cancellous bone? Cancellous bone is made up from trabeculae. – Cancellous bone is “spongy”. – Sparse compared to cortical bone (dense) Micro CT of cancellous bone.

8. Biomedical to mathematics connection Textons – Characterise patterns – Can be compared Textons were introduced by Bela Julesz in 1981 – Primarily in vision research

9. Textons Textons can be used for image recognition. – Surveillance – Object recognition – Diagnosing medical conditions Specifically, textons will be used to screen medical conditions in rats by using the collected bone data

10. Textons and bone data Textons can be generated from the rat data – Local textures are in 3D – Feature space is generated – Finding the number of clusters – Finding how well the textons separate the 3 experimental groups – Characterise the structure of cancellous bone according to the texture patterns