- Patlak plot
A

**Patlak plot**(sometimes called Gjedde-Patlak plot, Patlak-Rutland plot, or Patlak analysis) is a graphical analysis technique based on the compartment model that useslinear regression to identify and analyzepharmacokinetics problems involving irreversible uptake, such as in the case ofdeoxyglucose . It is used for the evaluation ofnuclear medicine imaging data after the injection of aradioactive orradioopaque tracer .The analysis is feasible if the behavior of the tracer can be approximated by two compartments, a "central" compartment that is in rapid equilibrium with

blood plasma , and a "peripheral" compartment where tracer enters without ever leaving during the time of the measurements. The amount of tracer in theregion of interest is accumulating according to the equation:$R(t)\; =\; K\; int\; c(t)dt\; +\; V\_0\; c(t)$

where $t$ is time, $R(t)$ is the amount of tracer in region of interest, $c(t)$ is the concentration of tracer in plasma or blood, $K$ is the clearance determining the rate of entry into the peripheral compartment, and $V\_0$ is the

distribution volume of the tracer in the central compartment. The first term of the right-hand side represents tracer in the peripheral compartment, and the second term tracer in the central compartment.By dividing both sides by $c(t)$, one obtains:

$\{R(t)\; over\; c(t)\}\; =\; K\; \{int\; c(t)dt\; over\; c(t)\}\; +\; V\_0$

The unknown constants $K$ and $V\_0$ can be obtained by

linear regression from a graph of $\{R(t)\; over\; c(t)\}$ against $\{int\; c(t)dt\; over\; c(t)\}$.**See also***

Logan plot

*Multi-compartment model

*Binding potential **References*** Cite journal

author = C. S. Patlak, R. G. Blasberg, J. D. Fenstermacher

title = Graphical evaluation of blood-to-brain transfer constants from multiple-time uptake data

journal =Journal of Cerebral Blood Flow and Metabolism

volume = 3

issue = 1

pages = 1–7

year =1983

month = March

* Cite journal

author = C. S. Patlak, R. G. Blasberg

title = Graphical evaluation of blood-to-brain transfer constants from multiple-time uptake data. Generalizations

journal =Journal of Cerebral Blood Flow and Metabolism

volume = 5

issue =4

pages = 584–590

year =1985 **External links*** PMOD, [

*http://www.pmod.com/technologies/doc/pkin/2326.htm Patlak Plot*] , PMOD Kinetic Modeling Tool (PKIN).

* " [*http://www.turkupetcentre.net/modelling/guide/patlak_plot.html Gjedde-Patlak plot*] ",Turku PET Centre .

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