imgdv 1.3.2 © 2003-2010 by Turku PET Centre

Estimation of distribution volume (Vt) or distribution volume ratio (DVR) from dynamic 2D PET images in ECAT 6.3 or 7.x format applying model independent graphical analysis approach of Logan et al [1, 2, 3] for reversible tracer uptake or binding. Simple non-iterative perpendicular line fitting algorithm [4] is applied in determination of the slope of the Logan plot. Parameters: 1) Input file (Plasma or Reference region TAC; times in minutes) 2) Dynamic image file 3) Linear fit start time (0 for automatic determination) 4) Parametric image file Options: -k2=<k2 of reference region> With reference region input it may be necessary to specify also the population average for reference region k2 [2] -Thr=<threshold%> Pixels with AUC less than (threshold/100 x max AUC) are set to zero. Default is 0 % -max=<Max value> Upper limit for Vt or DVR values. -min=<Min value> Lower limit for Vt or DVR values; 0 by default. -F Remove parametric pixel values that are over 4x higher than their closest neighbours. -E=<Fit end time (min)> Never use data after fit end time. -V=<filename> Y axis intercepts times -1 are written as an image in specified file. -N=<filename> Numbers of selected plot data points are written as an image. -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. Example: imgdv ua3818ap.kbq ua3818dy1.v 20 ua3818dv.v The unit of pixel values in the parametric Vt image is (mL plasma)/(mL tissue), and DVR images are unitless. In theory, DVR equals BP+1, and therefore a binding potential image can be computed from DVR image by subtraction of unity, e.g. using program ecatcalc. However, this may lead to a large number of pixels with negative values that may hamper the further statistical or visual analysis. 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: imgbfbp, imglhdv, ecat2tif, logan Keywords: image, modelling, distribution volume This program comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it under GNU General Public License.