If the 3D option is part of the PMOD license, the VOIs created in the PSEG tool can be conveniently visualized as a 3D scene. When activating the 
button in the lateral taskbar, a 3D View window is opened, the data loaded, and the VOIs rendered as surfaces together with the segmentation mask. The illustrations below use the result of the FUNCTIONAL (LOCAL MEANS) workflow, but the functionality is similar for PERCIST.
The image data is also available for the scene. Illustrated below is adding a volume-rendering (VR) of the MRI. The Input tab is selected, a Threshold level set such that all body pixels are included (Ovr check), the "Append" pushpin set for adding to the existing VOI renderings, and Volume HD activated.
The result after switching off the body mask and increasing the transparency of the VR object is illustrated below. Interactive exploration of such a scene will greatly add to the understanding of the lesion localization.
Please refer to the PMOD 3D Rendering Tool User's Guide for more information about how to explore and enrich the 3D scene.