fitfet 1.1  © 2000,2001 by Turku PET Centre

   
  Estimation of parameters of compartmental model for FETNIM PET studies,
  based on the FMISO model by Casciari, Graham and Rasey (1995).
  The higher hypoxia, the higher tissue/blood ratio and Ka.
   
    _____     F    _____   a*Ka    _____   Tissue FETNIM (FMISO):
   |  Cp | -----> | Cc  | ------> | Cbp |  dCc=(F/Vt)*(Cp-Cc)-(1-n)Ka*Cc
   |_____| <----- |_____|         |_____|  
              F      |                     Bound product:
                     | (1-a)*Ka            dCbp=a*Ka*Cc
                     V                     
                   _____                   Cellular diffusable product:
                  | Cdp |                  dCdp=(1-a)*Ka*Cc-Kb*Cdp
                  |_____|                  
                     |                     Extracellular diffusable product:
                     | Kb                  dCdpe=((1-n)/n)*Kb*Cdp
                     V                           -(F/(n*Vt))*Cdpe
                   _____                   
              F   | Cdpe|                  Total tissue activity:
           <----- |_____|                  Cpet=b1*Cb+
                                            b2*Vt*(Cc+(1-n)*(Cbp+Cdp)+n*Cdpe)
   
  The estimated parameters are:
    F, b1(=Va), b2, Ka 
  The fixed values are:
    Vt=1.0, a=0.36, n=0.50, Kb=0.013 
   
  Parameters are restricted to the following values:
    Parameter  Start value Lower limit Upper limit
      F         0.20        0.02        1.00      
      n         0.30        0.10        0.65      
      a         0.36        0.20        0.50      
      Ka        0.02        0.002       0.125     
      Kb        0.013       0.001       0.030     
  If any of the fitted estimates is very near to its limits, none of the
  parameters of that fit should be used; then '!' is printed as a warning.
   
  Program parameters:
    1) Plasma file
    2) Tissue TAC file (*.dft)
    3) Fit end time (duration)
    4) a (alpha; fraction of reactive intermediate converted to bound products)
    5) n (eta; extracellular volume fraction)
    6) Kb (rate for transport of diffusable product out of the cell)
    7) Result file 
    8) Fitted tissue TAC file (optional) 
   
  e.g.:
  fitfet uo0366ap.dat uo0366.dft 999 0.36 0.50 0.013 uo0366.res uo0366fit.dft
   
  Estimated parameter values for each region found in DFT file are written
  in the specified result file; results are appended to the end of file,
  if it exists already.
  Fitted curves are written in DFT format, if filename is given.