imgsrtm - tpcclib 0.8.0 © 2023 by Turku PET Centre
Computation of parametric image of binding potential (BPnd) from
dynamic PET image in ECAT, NIfTI, or Analyze format applying simplified
reference tissue model (SRTM) [1]:
______ K1' ___________
| | --> | | dCt(t)=
| | <-- | Cr | +R1*dCr(t)
| | k2'|___________| +k2*Cr(t)
| | ____________________ -(k2/(1+BPnd))*Ct(t)
| Cp | K1 | k3 | | Ct(t)=Cf(t)+Cb(t)
| | --> | Cf -------> Cb |
| | <-- | <------- |
| | k2 | | k4 | R1=K1/K1'=k2/k2'
|______| |___________|________| BPnd=k3/k4
The model is transformed to general linear least squares functions [2],
which are solved using Lawson-Hanson non-negative least squares (NNLS)
algorithm [3]. BPnd is estimated directly without division [4].
Dynamic PET image and reference region TAC must be corrected for decay.
Usage: imgsrtm [Options] imgfile rtacfile bpfile
Options:
-SRTM2
STRM2 method (5) is applied; in brief, traditional SRTM method is
used first to calculate median k2' from all pixels where BPnd>0; then
SRTM is run another time with fixed k2'
-R1=<filename>
Programs computes also an R1 image.
-k2=<filename>
Programs computes also a k2 image.
-k2s=<filename>
Program computes also a k2' image
-theta3=<filename> or -t3=<filename>
Program computes also a theta3 image; theta3 = k2/(1+BPnd)+lambda
-rp=<filename>
Program writes regression parameters in the specified image file
-dual=<filename> or -du=<filename>
Program writes number of i in set p in NNLS dual solution vector in
the specified image file
-thr=<threshold%>
Pixels with AUC less than (threshold/100 x ref AUC) are set to zero
default is 0%
-DVR
Instead of BP, program saves the DVR (=BP+1) values.
-end=<Fit end time (min)>
Use data from 0 to end time; by default, model is fitted to all frames.
-h, --help
Display usage information on standard output and exit.
-v, --version
Display version and compile information on standard output and exit.
-d[n], --debug[=n], --verbose[=n]
Set the level (n) of debugging messages and listings.
-q, --quiet
Suppress displaying normal results on standard output.
-s, --silent
Suppress displaying anything except errors.
Example:
imgsrtm ua2918dy1.v ua2918cer.dft ua2918bp.v
References:
1. Lammertsma AA, Hume SP. Simplified reference tissue model for PET
receptor studies. NeuroImage 1996;4:153-158.
2. Blomqvist G. On the construction of functional maps in positron emission
tomography. J Cereb Blood Flow Metab 1984;4:629-632.
3. Lawson CL & Hanson RJ. Solving least squares problems.
Prentice-Hall, 1974.
4. Zhou Y, Brasic J, Endres CJ, Kuwabara H, Kimes A, Contoreggi C, Maini A,
Ernst M, Wong DF. Binding potential image based statistical mapping for
detection of dopamine release by [11C]raclopride dynamic PET.
NeuroImage 2002;16:S91.
5. Wu Y, Carson RE. Noise reduction in the simplified reference tissue
model for neuroreceptor functional imaging. J Cereb Blood Flow Metab.
2002;22:1440-1452.
See also: imgdv, imgbfbp, imgratio, imgunit, eframe, imgdecay, img2dft
Keywords: image, modelling, binding potential, SRTM, SRTM2, reference input