fit_dtpa 3.3.5 © 2001-2010 by Turku PET Centre

Estimates the parameters of the myocardial perfusion model for Gd-DTPA using regional signal intensity curves from LV and myocardium measured with MRI and SAT-turboFLASH. Fitted parameters are unidirectional influx constant Ki (mL/mL/min), extravascular extracellular volume fraction Ve (mL/mL), venous blood volume fraction Vb (%), and time delay dT (sec). Parameters: 1) Datafile, containing measurement data from myocardial region(s) 2) LV datafile, or LV region name in previous datafile 3) Number of baseline samples (usually 3) 4) Fit duration (sec; time from beginning to use in fitting) 5) Result file (overwritten, if existing) [6) Fitted SI datafile (optional)] Options (with default or example values): -Alpha=8 (in degrees) -TR=0.0020 -TI=0.055 -R10myo=1.0 -R10b=0.67 -n=48 -r1=4.3 -HCT=0.38 -E=0.50 -Vb=6 ; if Vb is not set, it is fitted as one of the model parameters. -Vbmax=50 ; if Vb is fitted, the maximum for it can be changed with this option. Default is 50%. -dT=0 ; if dT is not set, it is fitted as one of the model parameters. -dTmin=0.5 ; if dT is fitted, the minimum for it can be changed with this option. Default is 0.5 s. -N ; SD and 95% CLs are not calculated. -F=basal.res If specified, then the values of Omega*M0 are read from the results of the first study, and are used to calculate R10b and R10myo. This corrects the background from the first study. For this purpose, the result file must not be in HTML format. -FVe Further, Ve is constrained to +-10% of the basal Ve value. -Vemin=0.10 ; minimum for Ve can be changed with this option. Default 0.10. -Vemax=0.40 ; maximum for Ve can be changed with this option. Default 0.40. -ODE=<am|conv> The second-order Adams-Moulton (am, default) or convolution (conv) is used to numerically solve the first-order ordinary differential equations. Datafile(s) must contain the sample times (sec) in the first column, and in the following columns the myocardial or LV signals. Detailed description of the datafile format is available in http://www.turkupetcentre.net/analysis/doc/format_dft.html Reference: Larsson HBW, Rosenbaum S, Fritz-Hansen T. Quantification of the effect of water exchange in dynamic contrast MRI perfusion measurements in the brain and heart. Magn. Reson. Med. 2001;46:272-281. See also: dtpa_s2c, dtpa_c2s Keywords: MRI, DFT, modelling, perfusion