logan 2.0.11 © 2000-2013 by Turku PET Centre
Calculates the distribution volume Vt or distribution volume ratio (DVR=BP+1)
using multiple-time graphical analysis (MTGA) for reversible PET
ligands (Logan 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
5) Result file (existing file is overwritten)
Options:
-k2=<reference region k2>
With reference region input, the population average of reference
region k2 (or k2/(1+k5/k6) in 3-compartment model) is set.
-BPnd
With reference input, BPnd (=DVR-1) is reported instead of DVR
-BPnd=<reference region name>
With plasma input, BPnd can be calculated as DVroi/DVref-1
-DVR=<reference region name>
With plasma input, DVR can be calculated as DVroi/DVref
-BPp=<reference region name>
With plasma input, BPp can be calculated as DVroi-DVref
-sd=<y|n>
Standard deviations are saved (y, default) or not saved (n) in results.
-mid[=<y|n>]
Mid frame times are used (y) or not used (n, default) even if frame
start and end times are available.
-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
-M Median of two-point slopes and intercepts (Cornish-Bowden)
-P Perpendicular regression model (4)
-R Iterative method (York 1966, Lybanon 1984, Reed 1992); default
If tissue file contains weights, the iterative method (-R) is weighted.
With other fitting methods the weights are not used.
With options -C and -R program can automatically find the linear plot
range, if fit start time is set to zero.
Example 1: tissue curves are in ut2345.dft and plasma curve in ut2345ap.dat;
fitted data range is from 10 to 60 min; standard deviations are not needed:
logan -nosd ut2345.dft ut2345ap.dat 10 60 ut2345.res
Example 2: tissue curves in ut1234.dft, including reference region 'cer';
reference tissue k2 is assume to equal 0.163;
plot is saved for viewing in ut1234pplot.svg:
logan -svg=ut2345lplot.svg ut2345.dft cer -k2=0.163 20 60 ut2345.res
References:
1. Logan J, Fowler JS, Volkow ND, Wolf AP, Dewey SL, Schlyer DJ,
MacGregor RR, Hitzemann R, Bendriem B, Gatley SJ, Christman DR.
Graphical analysis of reversible radioligand binding from time-activity
measurements applied to [N-11C-methyl]-(-)-cocaine PET studies in human
subjects. J Cereb Blood Flow Metab 1990; 10: 740-747.
2. Logan J, Fowler JS, Volkow ND, Wang GJ, Ding YS, Alexoff DL.
Distribution volume ratios without blood sampling from graphical
analysis of PET data. J Cereb Blood Flow Metab. 1996; 16: 834-840.
3. Logan J. Graphical analysis of PET data applied to reversible and
irreversible tracers. Nucl Med Biol 2000; 27:661-670.
4. Varga J & Szabo Z. Modified regression model for the Logan plot.
J Cereb Blood Flow Metab 2002; 22:240-244.
See also:
imgdv,
fitk4,
lhsoldv,
patlak,
rescoll,
res2html
Keywords: DFT, modelling, distribution volume, DVR
This program comes with ABSOLUTELY NO WARRANTY. This is free software, and
you are welcome to redistribute it under GNU General Public License.