fitshape 2.3.0 © 2001-2009 by Turku PET Centre
Estimates the enzyme activity (k3) from regional brain PET studies
using the shape analysis method (1,2). This model assumes that:
1) there is no metabolic product in the tissue at time 0
2) metabolite is retained in tissue completely
3) tissue radioactivity consists of parent tracer and metabolite, i.e.
Ct(t) = Cs(t) + Cm(t)
4) The increment of Cm during scan frame n can be calculated as:
Cm(n)-Cm(n-1) = k3*Cs(n-1)*DT(n) , where DT is the duration of frame.
1) Tissue TAC file
2) Fit time (in minutes from injection)
3) Result file (existing file is overwritten)
-h or --help
Print this message and exit
Tissue TACs will be smoothed by fitting to biexponential function
as suggested in (2), or exponential function plus constant (default),
or biexponential with constant; or not smoothed, in which case TACs
should have been previously smoothed and interpolated to frequent
Weight by sampling interval.
Set the interpolated sample time frequency; 0.1 by default.
Set the exponential fit start time (min); by default 3 min from
injection, suitable for biexponential fits (2). For single exponential
20 min or later is recommended unless option -wf is used.
Original data and fitted curves are plotted in specified file in
Scalable Vector Graphics (SVG) 1.1 format;
specification in http://www.w3.org/TR/SVG/
Fitted regional TACs are written in DFT format.
Interpolated regional TACs are written in DFT format.
--version or --build
Print software build information and exit.
Program works silently, printing only error and warning messages.
Program prints more information about what it is doing.
Format of the TAC data and result files are specified in
fitshape -svg=ua1309shape.svg ua1309.dft 999 ua1309shape.res
1. Koeppe RA, Frey KA, Snyder SE, Meyer P, Kilbourn MR, Kuhl DE.
Kinetic modeling of N-[11C]methylpiperidin-4-yl propionate: alternatives
for analysis of an irreversible positron emission tomography tracer for
measurement of acetylcholinesterase activity in human brain.
J Cereb Blood Flow Metab. 1999;19:1150-1163.
2. Tanaka N, Fukushi K, Shinotoh H, Nagatsuka S, Namba H, Iyo M, Aotsuka A,
Ota T, Tanada S, Irie T. Positron emission tomographic measurement of
brain acetylcholinesterase activity using N-[11C]methylpiperidin-4-yl
acetate without arterial blood sampling: methodology of shape analysis
and its diagnostic power for Alzheimer's disease.
J Cereb Blood Flow Metab. 2001;21:295-306.
See also: simshape
Keywords: DFT, modelling, reference input, enzyme activity, shape analysis
This program comes with ABSOLUTELY NO WARRANTY. This is free software, and
you are welcome to redistribute it under GNU General Public License.