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PXMOD Implementation

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.

PXMOD MRTM Model Pre-processing

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.

BPnd

Binding potential of the receptor-rich region TAC (BPnd = k3/k4 ).

Threshold

Discrimination threshold for background masking.

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.

PXMOD MRTM Model Pre-processing Result

Map Parameters

PXMOD MRTM Model Parameters

BPnd

Binding potential BPnd = k3/k4 .

k2'

Clearance rate of the reference tissue.

-Vt/(Vt'b)

First multi-linear regression coefficient of the operational equation (Ichise Eq.2.)

1/b

Second multi-linear regression coefficient of the operational equation (Ichise Eq.2.)

-Vt/(Vt'k2'b)

Third multi-linear regression coefficient of the operational equation (Ichise Eq.2.)