fvar4dat 1.4.0 © 2002-2012 by Turku PET Centre
Program for adding Gaussian noise to PET time-activity (TAC) data
using equations (1, 2):
SD(t) = TAC(t) * sqrt(Pc/(TAC(t)*exp(-lambda*t)*deltat)
TAC_noisy(t) = TAC(t) + SD(t)*G(0,1) ,
where Pc is the proportionality constant that determines the level,
of noise, Deltat is the scan frame length, and G(0,1) is a pseudo random
number from a gaussian distribution with zero mean and SD of one.
TAC data must be in DFT (3) or PMOD format, and it must contain frame start
and end times. TACs are assumed to be decay corrected.
Usage:
fvar4dat <Datafile> <Pc> <Isotope> <Output file>
Options:
-S[eed]=<seed for random number generator>
Computer clock is used by default
-sec
If datafile does not contain time unit, times are by default assumed to
be in minutes. Use this option to set time unit to sec.
-R=<nr of repeats>
Specified number of output files (*_NNNN.*) with different set of
noise are created
-common=<y|N>
Common noise SD based on TAC mean is used (y) or not used (n, default)
-minsd=<SD>
Set a minimum SD to add a minimum level of noise also to the TAC
time frames with no activity
-h or --help
Print this message and exit
--version or --build
Print software build information and exit
--silent
Program works silently, printing only error and warning messages
--verbose
Program prints more information about what it is doing.
If the output filename extension is *.sd or *.cv, then noise is not added
but calculated values of SD or CV (for noise) are saved instead.
TAC file format is specified in
References:
1. Chen K, Huang SC, Yu DC. Phys Med Biol 1991;36:1183-1200.
2. Varga J, Szabo Z. J Cereb Blood Flow Metab 2002;22:240-244.
3.
http://www.turkupetcentre.net/analysis/doc/format_dft.html
See also:
var4dat,
mvar4dat,
wvar4dat,
dftstd,
avgttac,
dft2csv,
fvar4img
Keywords: TAC, DFT, noise, simulation
This program comes with ABSOLUTELY NO WARRANTY. This is free software, and
you are welcome to redistribute it under GNU General Public License.
