Model calculation for regional TTACs

Regional tissue time-activity curves are less noisy than data from individual image voxels, enabling application of more complex analysis techniques than with dynamic PET images.

Common analysis methods for TTACs

Models for reversible tracer uptake

Outcome is the volume of distribution, binding potential, or a related parameter.

Without blood sampling

Reference tissue input compartmental models; SRTM can be fitted to data using PMOD, or TPC software fit_srtm (nonlinear fitting) or bfmsrtm (basis function method); original RTCM can be fitted also using PMOD, or TPC software fit_frtm
MTGA: Logan plot analysis
Tissue/Reference tissue and (Tissue-Reference tissue)/Reference tissue: dftratio

With metabolite corrected plasma input

Full compartmental model fit
Compartmental model fit with fixed K₁/k₂
MTGA: Logan plot analysis
Late-scan tissue/plasma ratio; may correlate with volume of distribution

Models for irreversible tracer uptake

Outcome is the K_i, FUR, k₃, or a related parameter, representing metabolic rate (MR), or enzyme or transporter activity.

Without blood sampling

Reference tissue input compartment models: depending on the available reference tissue, use either fit_rrtm or fit_trtm with command-line parameters and options as instructed.
MTGA: Gjedde-Patlak plot analysis
Patlak plot with k_Loss estimation
Shape analysis method

With metabolite corrected plasma input

Standardized uptake values

Regional SUV
% of injected dose / g of tissue (%i.d./g): dftsuv

Miscellaneous utility software for regional modeling

Correction of blood radioactivity in regional TACs: taccbv
Correction of recovery and spill-over in myocardial TACs: heartcor
Calculation of bound curve (Bound=Total-Reference): dftbound
Calculation of tissue-to-plasma ratio
Simulation tools
Plotting of TACs and fitted curves

See also:

Tags: TTAC, Analysis

Updated at: 2020-05-01
Created at: 2007-09-26
Written by: Vesa Oikonen