Brain VOI Editing and Statistics Calculation

VOIS page shows a fusion of the MR image and the average PET in the chosen result space, as well as the outlined brain structures.

VOI Editing and Selection

At this time the contour VOIs can be interactively adjusted using the VOI features of PMOD, which are described in the PMOD Base Functionality Guide and in the Introduction. Note that the List tab should be selected for the adjustment, and that depending on the configuration only a reduced set of VOI tools is available.

Statistics Calculation

Once the VOIs are acceptable, it is recommended to first save them and then proceed with statistics calculation by the Statistics action button. The result (of the selected VOIs only) is shown on the separate Statistics page of the PNEURO tool, from where it can be further evaluated.

Partial-Volume Correction (PVC) Option

The PNEURO tool supports the GTM-based patial-volume correction (PVC) of the PET signal.

The PVC selection has three choices:

• NONE: No partial-volume correction is applied (default).
• LMA GTM: A variant of the Rousset correction method is applied, whereby only a percentage of the pixels in the inner of the VOI is used for calculating the VOI average. This percentage can be set by the Voxels to be kept parameter.
• VOI BASED: The original Rousset correction method is applied.

If a PVC method is used, both the original and the corrected statistics are calculated. Note that due to the high number of VOIs the PVC calculation may take several minutes and consumes a significant amount of RAM.