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Equations for the transport of scerma
1. I need to be efficient
∆r
generated at each point along a
transport line
1
θ
∆r2 Under the collapsed cone approximation:
• Scerma does not vary with θ within ΔΩ
r
1
2
(Bθ, bθ constant along transport line)
and scerma generated, emitted and
absorbed along transport line
and assuming:
• Scerma generated per unit r is constant
Averaging scerma from voxel 1, over points
ithi Δ 2 i l 2
within the same voxel (scerma does not
vary considerably within voxels)
'
2Δr r
)]' exp( )]1 exp( 1[
1sc,1 S
ρ2
ρ1
'
2Δr r
211scD dr rb r b
b
B
dr 

     

  


w n r n voxe :
)]2 exp( 1)][1 exp( 1)[ exp(
1sc 1 S ρ1
2Δr
r
2Δr
r
211scD
r b r b rb B        
  
   
2 2 , ρ2 r b 
