Shane's is right. many factors are involved, and way too complicated for my taste. FDG-18 is the glucose tracer injected before the scan, which distrubutes throughout the body to highlight possible cancer, being tumors like suck up glucose. None of my PET/CT scans, I had 12 or so, sound exactly like these, and each facility is different too, and SUV would be the uptake from the FDG injection given, and would be repetive, and doesn't need to be said. It's like writing, there are many ways to tell the same story, and end the same.