# lhsolki 1.3.0 © 2002-2005 by Turku PET Centre

Estimates the influx rate constant (Ki) from compartmental model:
Cp Ct
______ ___________________
| | K1 | | 1-tissue CM
| | --> | k3 | Ki=K1
| A | <-- | A -------> B |
| | k2 | | 2-tissue CM
|______| |___________________| Ki=(K1*k3)/(k2+k3)
The model is transformed to general linear least squares functions [1],
which are solved using Lawson-Hanson non-negative least squares (NNLS)
algorithm [2]. Ki is estimated directly without division [3].
Parameters:
1) Metabolite corrected plasma file
2) Tissue TAC file (*.dft)
3) Fit end time (duration)
4) Result file (existing file is overwritten)
e.g.: lhsolki ub2917ap_pure.kbq ub2917.dft 90 ub2917ki.res
Options:
-0 Akaike weighted avg of 1- and 2-tissue compartment model results [4,5]
-1 Force one-tissue compartment model for all regions
-2 Force two-tissue compartment model for all regions (default)
-A Automatic selection of model for separate regions
References:
1. Blomqvist G. On the construction of functional maps in positron emission
tomography. J Cereb Blood Flow Metab 1984;4:629-632.
2. Lawson CL & Hanson RJ. Solving least squares problems.
Prentice-Hall, 1974.
3. 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.
4. Turkheimer FE, Hinz R, Cunningham VJ. On the undecidability among
kinetic models: from model selection to model averaging. J Cereb Blood
Flow Metab 2003; 23: 490-498.
5. Sederholm K. TPCMOD0016 2003-03-20.
See also:

dftcbv,

dftweigh,

dft2ps,

patlak,

fitk3,

imglhki
Keywords: DFT, modelling, irreversible uptake