Image processing

1. V2MIP
Variational Methods for Medical Image Processing
A. Almeida, J. I. Barbosa, A. Carvalho, M. A. R. Loja, R. Portal J. A.
Rodrigues and L. Vieira

2. Summary
• The Medical Problem
• The Mathematical Problem
• Preliminary Results
• Conclusions

3. Acknowledgements
• This research was supported by project V2MIP, IDI&
CA-IPL 2017.

4. The Medical Problem
V2MIP - Variational Methods for Medical Image Processing

5. The Medical Problem
• Parasites can be detected:
• Blood smears
• Hydatid fluid
• Requires trained operators
• Detect the parasite
• Distinguish between species

6. The Medical Problem
• Identification is a Manual Process
• Deadly variants can be mistaken
for less prejudicial parasites
• Misdiagnosis
• Preventable deaths

7. The Medical Problem
• Echinococcosis – Hydatid Disease
• Parasitic disease of tapeworms
• Affects mainly the liver and lungs
of mammals
• The larvae stage forms fluid-filled
cysts

8. The Medical Problem
• Malaria
• Blood-borne parasitic disease
• Plasmodium
• Transmitted by mosquito bites
• One of the main causes of disease related deaths:
• Africa
• Southern Europe - until the beginning of the XX century

9. The Mathematical Problem
V2MIP - Variational Methods for Medical Image Processing

10. The Mathematical Problem
• Starting from a gray-level 2D image
• Intensity function:
• Minimize the Energy Functional

11. The Mathematical Problem
• The objective is to find u such that:

12. The Mathematical Problem
• FreeFem++ Software
• Open Source
• Highly flexible Finite Element Method solver
solve pb1(uh,vh,solver=CG) =
int2d(Th)(alpha*grad(uh)'*grad(vh)) +
int2d(Th)(lambda*(uh*vh)) –
int2d(Th)(lambda*(f*vh)) +
on(1,uh=0) ;

13. Preliminary Results
V2MIP - Variational Methods for Medical Image Processing

14. Preliminary Results
• Hydatid Fluid
• Cyst walls and infected areas
correspond to large local variations
in the solution
• Cysts can be isolated
• Mesh refined to enhance the solution

15. Preliminary Results
• Hydatid Fluid
• Find closed isolines at a
predetermined threshold
• The parasites are marked by a large
change in the solution
nc = isoline (Th, uh, iso = vm, close =1, Curves,
beginend = be, smoothing=.005, ratio =0.1) ;

16. Preliminary Results
• Blood Smear
• Reapply the same analysis
process

17. Preliminary Results
• Blood Smears
• Many more cells to analyze
• Search criterion

18. Preliminary Results
• Blood Smears
• The parasite corresponds to a large
change in the solution

19. Preliminary Results
• Blood Smears
• False positives…
• This method also detects platelets

20. Conclusions
V2MIP - Variational Methods for Medical Image Processing

21. Conclusions and Future Work
• Devise an automatic method to detect parasitic
infections
• Correctly detects Hydatid disease parasite
• For the malaria parasites, the search
criterion has to be tuned to eliminate
false positives

22. V2MIP
Variational Methods for Medical Image Processing
A. Almeida, J. I. Barbosa, A. Carvalho, M. A. R. Loja, R. Portal J. A.
Rodrigues and L. Vieira