Analysis Selection

Note the tabs labeled with the different PET tracers and GATED.

Please select the tab corresponding to the data to determine the processing method, the tracer name in case of dynamic data. The tracer-specific processing settings are then accessible in the panel and may be adjusted.

• Model: the list selection offers all kinetic models suitable for the selected tracer. The ? button shows a summary description of the currently selected model.
• Active parameter name: The cardiac tool has the capability to disregard a parameter value in the statistics when it is clearly outside the physiological range. The string entered in the Active parameter name text field defines which parameter is undergoing this restriction. The allowed range needs then to be configured in In range from .. to.

There are two sections for defining the defaults for the averaging strategy. The idea is to calculate images showing sufficient anatomical information by a weighted combination of some of the dynamic acquisitions as described in Generation of Blood Volume and Myocardium Images.

• Blood Average Parameters: The definition has a Start time, and End time, and an optional Smooth parameter. In the example above all frames between 0 and 35 seconds (frame start times) will be averaged, and then smoothed with a 3D Gaussian filter of 3mm full-width at half maximum. The result is assumed to represent an anatomical image of the blood volume.
• Myocardium Average Parameters: Similar to Blood, the Myocardium image is generated by averaging the frames between the Start and End time specified underneath. As there may exist some activity in the cavities, a fraction of the blood volume image can be subtracted to improve the contrast. In the example above a fraction of 0.05 of the image generated by the Blood configuration will be subtracted.

MBF Special Cases

1. In the case of the NH3 tracer there is a box Calculate Pixelwise Parametrical MBP Map. If it is checked a MBF map will be calculated within the area of the left ventricle using a basis function method. Based on the MBF map, the perfusion across the heart wall can be analyzed. This functionality is enabled with the Automatic transmural analysis box.
2. The H2O tracer has as an additional choice Factor analysis. Please refer to Pre-Processing Steps with Factor Analysis (Water only) for more information how a factor analysis can be employed for the generation of blood volume and myocardium images.