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Acquisition and Data Requirements
Image Data |
A dynamic data set acquired long enough that the equilibrium relation is approximately fulfilled. |
TAC 1 |
TAC from a receptor-rich region (such as basal ganglia for D2 receptors). |
TAC 2 |
TAC from a receptor-devoid region (such as cerebellum or frontal cortex for D2 receptors). |
k2' |
A average value of the efflux rate constant from regions without receptors, which has been previously determined. |
Model Preprocessing
Two regional TACs (TAC1 and TAC2) are needed for Model Preprocessing.
k2' |
The average value of the efflux constant k2. It must have been determined separately and is only an input parameter to be manually entered. Note that the value of k2' also has an impact on fitting t*. |
t* |
The linear regression estimation should be restricted to a range after an equilibration time. t* marks the beginning of the range used in the linear regression analysis. It can be fitted based on the Max. Err. criterion. Note: Time is in acquisition time, not in the normalized time of the graphical plot. |
Max. Err. |
Maximum relative error allowed between the linear regression and the Logan-transformed measurements in the segment starting from t*. |
Threshold |
Discrimination threshold for background masking. |
BPnd |
Binding potential, calculated by as: BPnd = k3/k4 = DVR-1.0 |
intercept |
The intercept of the linear regression (Logan Eq.6.) |
Start |
Time in the plot which corresponds to t*. |
The result of the fit during Model Preprocessing is shown in the Result panel for inspection.
Map Parameters
BPnd |
Binding potential, calculated by as: BPnd = k3/k4 = DVR-1.0 where DVR is the slope of the fitted regression line. |
intercept |
Intercept of the linear regression (Logan Eq.6.) |