## convexpf - tpcclib 0.7.9 © 2022 by Turku PET Centre

Convolution of PET time-activity curve (TAC) with response function h(t)
consisting of sum of three decaying exponential functions
h(t) = a1*exp(-b1*t) + a2*exp(-b2*t) + a3*exp(-b3*t)
Function integral from 0 to infinity is a1/b1 + a2/b2 + a3/b3.
Output TAC, Co(t), is calculated from input TAC, Ci(t), as
Co(T) = Ci(T) (x) h(T)
, where (x) denotes the operation of convolution.
To use sum of two exponentials as the response function, enter zeroes for
a3 and b3. To use a mono-exponential, set a2 and b2 to zero, too.
Usage: convexpf [Options] tacfile a1 b1 a2 b2 a3 b3 outputfile
Options:
-i=<Interval>
Sample time interval in convolution; by default the shortest interval
in the plasma data; too long interval as compared to b's leads to bias.
-auc=1
Scale response function to have integral from 0 to infinity to unity;
that will lead to similar AUC for the input and output TACs.
-h0=1
Scale response function to h(0)=1.
-h, --help
Display usage information on standard output and exit.
-v, --version
Display version and compile information on standard output and exit.
-d[n], --debug[=n], --verbose[=n]
Set the level (n) of debugging messages and listings.
-q, --quiet
Suppress displaying normal results on standard output.
-s, --silent
Suppress displaying anything except errors.
The units of a's and b's must be compatible with units of the TAC, and
the optional sample interval.
For accurate results, input TAC should have very short sampling intervals.
Frame durations are not used, even if available in the TAC file.
Example:
convexpf -auc=1 plasma.tac 1 0.05 0 0 0 0 simulated.tac
See also: sim_3tcm, fit2dat, tacadd, simdisp, simframe, sim_av, convsurg
Keywords: TAC, simulation, modelling, convolution