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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). |
Model Preprocessing
Two regional TACs (TAC1 and TAC2) are needed for Model Preprocessing.
t* |
The least squares estimation should be restricted to a range after an equilibration time. t* marks the beginning of the range used in the multi-linear regression analysis. It can be fitted based on the Max. Err. criterion. |
Max. Err. |
The maximal relative error allowed if t* is fitted. |
k2' |
Clearance rate of the receptor-less reference tissue. If the fit box is checked, k2' is estimated in Model Preprocessing using MRTM, otherwise MRTM2 is applied with the fixed k2' which is entered by the user. The value of k2' resulting from Model Preprocessing will be used for the pixel-wise MRTM2 analysis. Note the recommendation of Dr. Ichise to determine k2' as the average of k2' determined with MRTM in several regions with high BP. As a convenience, however, k2' may be fitted with a single TAC in Model Preprocessing. |
Threshold |
Discrimination threshold for background masking. |
BPnd |
Binding potential of the receptor-rich region TAC (BPnd = k3/k4 ). |
The result of the multi-linear fit during Model Preprocessing is shown in the Result panel for inspection. The initial points which are not taken into account (before the t* time) are set to 0.
Map Parameters
BPnd |
Binding potential BPnd = k3/k4 . |
R1 |
R1 = K1/K1' relative ligand delivery (for 1-tissue kinetics). The calculated image often looks similar to a perfusion image and can sometimes used for matching purposes. It is recommended to restrict the range of fitted values. |
k2 |
Clearance rate in the pixel (for 1-tissue kinetics). |