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List of PKIN Compartment Models

PKIN features a comprehensive set of compartment models as listed below. The number of tissue compartments ranges from 1 to 3. There are different variants of the same model structure, so that prior information can be entered easily, and that coupling of physiologic parameters across region is possible.

For instance, the 2-tissue compartment model has the standard parameters K1, k2, k3, k4 . An equivalent description is by the parameters K1, K1/k2, k3, k4 . The advantage is, that the K1/k2, represents the distribution volume of the non-displacement compartment in tissue (free and non-specifically bound tracer), which can often be assumed to be the same across different tissues. Therefore, K1/k2 can be included as a common parameter in a coupled fit, hereby reducing the number of fitted parameters and thus potentially improving the identifiability of all.

Model Name

Description

1-Tissue Compartment

Most basic compartment model with the blood compartment and one tissue compartment.

2-Tissue Compartments

Compartment model with the blood compartment and two sequential tissue compartments. Often used for receptor studies.

FDG-2 Tissue Compartments

The 2-Tissue compartment model including the plasma glucose and the lumped constant to calculate the metabolic rate of glucose.

2-Tissue Compartments, K1/k2

The same model as the 2-Tissue compartment model, except that K1/k2 is used as a model parameter instead of k2. This facilitates coupled fitting.

2-Tissue Compartments, K1/k2 &Vs

The same model as the 2-Tissue compartment model, except that K1/k2 and the specific distribution volume are used as model parameters instead of k2 and k4. This facilitates coupled fitting and the easy generation of synthetic model curves.

Linear Least Squares

2-Tissue Compartment model solved by the Linear Least Squares method.

2-Tissue Compartments, Bmax

Non-linear 2-Tissue compartment model for receptor tracer studies taking care of the saturation of receptor sites.

3-Tissue Compartments

Most detailed compartment model which separates free tracer in tissue from non-specific binding.

Flow & Dispersion

Specific for dynamic H215O- PET Data with implicit deconvolution of the input curve dispersion

Model with Metabolites, 3 Compartments

Extends the 2 tissue compartment model by an additional input of labeled metabolites from the plasma.

Model with Metabolites, 3 Compartments and Constraints

Same model as above, with constraints usable for fixing or coupled fitting.

Model with Metabolites, 4 Compartments

2-compartment model for authentic ligand and metabolites, linked by a transfer constant between the tissue compartments

Delforge Triple- injection Protocol for Flumazenil

During a single imaging study three injections are applied: hot ligand first, then cold ligand for displacement, then a mixture of cold & hot ligand. The individual receptor parameters can be estimated.