General Assumptions in PKIN
The following is generally assumed:
- All loaded data has been decay corrected to the same time point. This means that the PET scanner and the blood sampling times must have been synchronized.
- The acquisition time intervals may have gaps, but must not overlap.
- The input curve CP(t) represents the authentic tracer in arterial plasma which is available for exchange with tissue.
- The whole blood curve CBlood(t) represents the activity concentration of the tracer and all its metabolites in whole blood.
- In compartment models the whole-blood signal contribution can optionally be considered in the operational equation by
CModel = vB*CBlood +(1-vB)*CTissue
where vB represents the fractional volume of the blood space in the VOI, CBlood(t) the whole blood concentration, and CTissue(t) the summed concentrations in all tissue compartments.
- The results of non-cardiac flow models are returned per cm3 tissue. To convert to flow per g tissue the values must be divided by the tissue density.
Exceptions to these rules are specified in the description of the individual models.