p2t_vp3c 1.1.0 © 2001,2005 by Turku PET Centre
Simulation of PET tissue time-radioactivity concentration curve (TAC)
from arterial plasma (Ca) and blood (Cb) TACs, based on three-tissue
compartmental model, where the second and third compartments are parallel,
often used to represent specific and non-specific binding.
____ k1 ____ k3 ____
| Ca | ----> | C1 | ----> | C2 |
|____| <---- |____| <---- |____|
k2 k4
| ^
k5 | | k6 dC1(t)/dt = k1*Ca(T) - (k2+k3+k5)*C1(T) +
v | k4*C2(T) + k6*C3(T)
____ dC2(t)/dt = k3*C1(T) - k4*C2(T)
| C3 | dC3(t)/dt = k5*C1(T) - k6*C3(T)
|____| Ct(T) = C1(T) + C2(T) + C3(T)
Cvb(T) = Cab(T) - dCt(t)/dt / f
Cpet(T) = Vb*fA*Cab(T) + Vb*(1-fA)*Cvb(T) + (1-Vb)*Ct(T)
Parameters:
1) Plasma TAC filename
2) Blood TAC filename
3-8) k1, k2, k3, k4, k5, k6
9) Blood flow f (ml/(min*ml));
set to 0 to assume that f>>K1 and Cvb=Cab
10) Vascular volume fraction Vb (%)
11) Arterial fraction of vasclar volume fA (%)
12) Filename for simulated TACs
Options:
-nosub
TACs of sub-compartments are not written into output file.
If the times in plasma file are in seconds, the units of rate constants
(k's) and blood flow (f) must be specified as 1/sec.
For accurate results, plasma data should have very short (e.g. 0.1 min)
time 'frames'.
To reduce the model, k5 or k3 can be set to 0.
Results are saved in DFT format, where the TACs are:
1) Total tissue activity concentration (Cpet)
2) Activity concentration in 1st tissue compartment, (1-Vb)*C1
3) Activity concentration in 2nd tissue compartment, (1-Vb)*C2
4) Activity concentration in 3rd tissue compartment, (1-Vb)*C3
5) Arterial concentrationcontribution to tissue activity, Vb*fA*Cab
6) Venous contribution to tissue activity, Vb*(1-fA)*Cvb
See also:
p2t_v3c,
p2t_p3c,
dftadd,
dftren,
fr4sim,
dft2img
Keywords: DFT, simulation