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Attenuation Correction
ESTRO Teaching Course Advanced Imaging: PET – Reconstruction, Contouring
8
∫
⋅ =
−
ox
x
dx x
ek P
)(
1
1
µ
∫
⋅ =
−
x
ux
dx x
e k P
)(
2
2
µ
∫
⋅ ⋅ = ⋅ =
−
ox
ux
dx x
tot
e kk PP P
)(
2 1
2 1
µ
Probability
P
1
for quant
γ
1
to reach a
detector:
γ
1
γ
2
x
x
U
x
O
Accordingly
P
2
for quant
γ
2
:
Probability for a coincidence event:
Accurate attenuation correction is possible if the line integral
can be obtained from a transmission measurement.
CT is used for attenuation correction!
∫
o
u
x
x
dxx
)(
µ