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Principe physiques de la radiologie numerique

Rappels

kVp
mA
Temps d'exposition

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

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Adaptation du faisceau:

Filtration uniforme (Cu)
Lames de collimation

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Interactions avec la matiere:

Diffusion elastique
Diffusion inelastique
Effet photoelectrique

Les chaines images selon les modalites

Quelques exemples

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Qu'est-ce qu'une "bonne" image ?

Tout depend de la tache

On a 3 choses tres importantes:

bruit
Image Not Showing Possible Reasons
- The image file may be corrupted
- The server hosting the image is unavailable
- The image path is incorrect
- The image format is not supported
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nettete
- Resolution spatiale
- Image Not Showing Possible Reasons
  The image file may be corrupted
  The server hosting the image is unavailable
  The image path is incorrect
  The image format is not supported
  Learn More →
contraste
- Contraste-to-noise ratio
  Image Not Showing Possible Reasons
  The image file may be corrupted
  The server hosting the image is unavailable
  The image path is incorrect
  The image format is not supported
  Learn More →

Bonne image a rayons X ?

Ca depend encore de la tache

Differentiation de matieres

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Pas d'artefacts (e.g., halos pres des contours, lignes, colonnes, mouvement, flou…)

Si on a un halo autout d'un implant, on a un peu de jeu autour
Il faut certainement rajouter quelque chose pour reparer ca
Ca peut etre tres dangereux (patient fragile, agee, etc.)

Zoom sur la chaine de traitement numerique

L'image qu'on voit est loin d'etre l'image qu'on mesure

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Sur la premiere image on a une ligne au centre

Image Not Showing Possible Reasons

The image file may be corrupted
The server hosting the image is unavailable
The image path is incorrect
The image format is not supported

Learn More →

Qualite Image et tache clinique

Qui est mon patient ?
- Un gamin
- Un adulte
- Une personne agee
Pour quel acte vient-il ?
- Un suivi de scoliose / un bilan general de posture
- Un depistage de cancer du sein
- Une ablation de tumeur hepatique

Selon les cas, le besoin en qualite image et la tolerance en terme d'irradtion serra differente

Un principe historique: ALARA (As Low As Reasonnably Achievable)
Un acronyme qui a tendance a etre remplace par ALADA (As Low As Diagnostically Achievable)

Du coup il y a des guidelines:

Image Not Showing Possible Reasons