fvar4img 1.3.0 © 2003-2012 by Turku PET Centre
Program for adding Gaussian noise to dynamic PET image
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, TAC(t) is the mean activity concentration in the image frame,
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.
Image must be in ECAT (6.3 or 7) format, or Analyze 7.5 format with SIF.
Image is assumed to be decay corrected to zero time.
Usage:
fvar4img [Options] <image file> <Pc> <output image>
Options:
-seed=<seed for random number generator>
Computer clock is used by default
-i=<O-15|N-13|C-11|F-18|Ge-68|Ga-68|Br-76|Rb-82|Cu-62>
Specifies the isotope
-minsd=<SD>
Set a minimum SD to add a minimum level of noise also to the image
frames with no activity
-efile=<TAC filename>
Save image mean TAC and SD that were used in noise simulation
-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.
Example:
fvar4img -i=C-11 simulated.v 5.0 noisy.v
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.
See also:
dft2img,
flo2ecat,
eframe,
edecay,
fvar4dat,
ecat2tif
Keywords: image, simulation, noise
This program comes with ABSOLUTELY NO WARRANTY. This is free software, and
you are welcome to redistribute it under GNU General Public License.