patlak 1.8.10 © 2001-2013 by Turku PET Centre
Calculates the influx (uptake) rate constant Ki (ml/(min*ml)) as slope of
the Gjedde-Patlak plot (1,2,3) from regional PET time-activity curves (TACs).
Parameters:
1) Tissue TAC file
2) Name of plasma file OR reference region name in TAC file
3-4) Start and end times for linear fit (min)
5) Result file (existing file is overwritten)
Options for calculation of metabolic rate:
-Ca=<value>
Concentration of native substrate in arterial plasma (mM),
for example plasma glucose in [18F]FDG studies.
With this option the metabolic rate (umol/(min*100 g)) is calculated.
-LC=<value>
Lumped Constant in MR calculation; default is 1.0.
-density=<value>
-d=<value>
Tissue density in MR calculation; default is 1.0 g/ml.
General options:
-ic=<y axis intercept>
Force y axis intercept to specified value; for FUR or Ri calculation
use regfur.
-sd=<y|n>
Standard deviations are saved (y, default) or not saved (n) in results.
-mid=<Y|n>
Frame middle times are used (y), or not used (n, default), even if frame
start and end times are available. For compatibility with old software.
-svg=<Filename>
Plots are written in specified file in Scalable Vector Graphics (SVG) 1.1
format; specification in
http://www.w3.org/TR/SVG/
-plotdata=<Filename>
Data for plots is written in specified file in XHTML table format for
easy importing in Excel or OpenOffice spreadsheet, where the data can
be viewed; if filename extension is .dft, data is written in DFT format
-h or --help
Print this message and exit.
-v, --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.
Options for selecting the least-squares line fit method:
-C Traditional regression model (default)
-M Median of two-point slopes and intercepts (Cornish-Bowden)
-P Perpendicular regression model (4)
-R Iterative method (York 1966, Lybanon 1984, Reed 1992)
In the present software version, the weights are not used in the fit.
Example 1: tissue curves are in ut1234.dat and plasma curve in ut1234ap.dat;
fitted data range is from 10 to 60 min; standard deviations are not needed:
patlak -nosd ut1234.dat ut1234ap.dat 10 60 ut1234.res
Example 2: tissue curves in ut1234.dft, including reference region 'cer';
plot is saved for viewing in ut1234pplot.svg:
patlak -svg=ut1234pplot.svg ut1234.dft cer 10 60 ut1234.res
References:
1. Gjedde A. Calculation of cerebral glucose phosphorylation from brain
uptake of glucose analogs in vivo: a re-examination. Brain Res. 1982;
257:237-274.
2. Patlak CS, Blasberg RG, Fenstermacher JD. Graphical evaluation of
blood-to-brain transfer constants from multiple-time uptake data.
J Cereb Blood Flow Metab 1983;3:1-7.
3. Patlak CS, Blasberg RG. Graphical evaluation of blood-to-brain transfer
constants from multiple-time uptake data. Generalizations.
J Cereb Blood Flow Metab 1985;5:584-590.
4. Varga J & Szabo Z. Modified regression model for the Logan plot.
J Cereb Blood Flow Metab 2002; 22:240-244.
See also:
imgki,
fitk3,
fitkloss,
lhsolki,
regfur,
logan,
rescoll,
dfttime
Keywords: DFT, modelling, irreversible uptake, net influx rate, Ki
This program comes with ABSOLUTELY NO WARRANTY. This is free software, and
you are welcome to redistribute it under GNU General Public License.