A.M.Cormack G.N.Hounsfield J. Radon. tomographie : sinogramme sinogramme 4 projections 90° 135°...

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A.M.Cormack G.N.Hounsfield J. Radon

Transcript of A.M.Cormack G.N.Hounsfield J. Radon. tomographie : sinogramme sinogramme 4 projections 90° 135°...

Page 1: A.M.Cormack G.N.Hounsfield J. Radon. tomographie : sinogramme sinogramme 4 projections 90° 135° 45° 0° 8 projections 16 projections 32 projections.

A.M.Cormack

G.N.HounsfieldJ. Radon

Page 2: A.M.Cormack G.N.Hounsfield J. Radon. tomographie : sinogramme sinogramme 4 projections 90° 135° 45° 0° 8 projections 16 projections 32 projections.

tomographie : sinogramme

sinogramme4 projections

4 projections

90°

90°135°

135°

45°

45°0°

8 projections

16 projections

32 projections

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tomographie : rétroprojection

0°45°

image initiale

sinogramme4 projections

90°

135°

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nombre de projections

4 projections

image initiale

8 projections 16 projections 32 projections

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non filtré rampe HanningImage initiale

filtragesinogramme

32 projections

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tomographie : acquisition des projections

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Tomographie : sélection d ’une coupe

sinogramme

rétroprojectionnon filtrée

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Tomographie : reconstruction d ’une coupe

non filtré

sinogramme

filtre rampe filtre de Hanning

rétro-projections

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maladie d ’Alzheimer

sujet normal

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unités Hounsfield

-1000 -600 -100 0 50 +1000

air

poumon graisse

eau

parenchymes

calcium

parenchyme pulmonaire

cerveau, foie, rein

os

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tomographie : rétroprojection 1

1 rétroprojection

2 rétroprojections

45°0°

image initiale

sinogramme4 projections

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tomographie : rétroprojection 2

3 rétroprojections

90°

45°0°

4 rétroprojections

90°

135°

45°0°

image initiale

sinogramme4 projections