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How to get a volume ?
- Turn around the patient
- X ray acquisition in different angles
Artifacts
Different types of artefact:
- Motion artifact
- Metal artifact
- Ring artifacts (detector)
State of the art
- Where
- Correction applied on volumes
Inpainting
- Fill selected image area
- Requires having the mask of the missing parts
Methods
Interpolation 2D
Interpolation algorithm from skimage to create a basline:
- Nearest neighbor
- Linear
U-NET 2D
Improvements ?
- Conv2D/3D do not consider the mask
- Losses (MSE/MAE) do not consider the mask
Partial convolution
- Presented by Nvidia in 2018
- Mask area is much less visible and overall results are improves
Keras ?
Loss improvement
- Using a train VGG
- deep learning classifier
- Layers used: 3rd, 6th and 10th
Data
Experiments
Goal
- 2D
- Perfomance machine learning
- Added value
- 3D
- Adding temporal gives best results
- Can we be more memory efficient using patches ?
Evaluation method
- Quantitative evaluation
- MSE
- MAE
- SSIM
- Structural similarity
- PSNR
- Peak To Signal Noise Ratio
- More quantitative than qualitative
- Quality eval
- Eval by human eye
Results
Qualitative 2D
Ribs reconstruction
Qualitative 2D+T
Analysis
- Machine learning can be used for this task
- PConv and VGG loss are the best improvements
Conclusion
- Implementation of PConv2D and PConv3D
- Promising resultls
- Kickstarted GE exploration and gave them insights on their future work
- Had fun with advance machine learning
Questions
Guillaume Tochon
Le papier a ete utilise sur des images de scan ?
Non sur des images naturelles
Expliquer ‘smoothing loss’
Dilatation verticale et horizontale des resultats
Elodie Puybareau
Generation des artefacts: probleme avec modele 2D+T, pourquoi blanc alors que modele 2D noir ?
Les modeles 2D sont aussi blanc sur les images
Eleves
Exemple d’applications concretes ?
Application de corrections permet d’avoir des images pouvant etre travaillees pour un medecin
Genration des artefacts aleatoires ?
Oui pour la position et rotation en 3D mais sinon non, pas de perte de temps a generer de la donnee
Tester avec des formes differentes ?
Oui avec des coins et des aiguilles
Generer un nombre infini de donnees, probleme de fit ?
Oui
Interpolation lineaire plus simple ?
Oui mais beaucoup de stries et n’arrive pas a reconstruire certaines parties
Retour GE Healthcare
Bonne organisation, bon avancement des projets mais baisse d’activite lors d’examens, groupe autonome