Both actually. My lungs lit up due to pnuemonia and my neck and jaw lit up because I was still healing from the mandiblectomy/neck dissection.

Remember all a PET scan does is measure how quickly cells in an area are sucking up sugar(uptake). Healing tissues, immflamation, pneumonia and other conditions can make an area light up and it doesn't have to be cancer. In fact just looking at my records I had an area in my neck that was a 3.2 uptake that was still the swelling from the dissection. My ENT and RO (both I love) told me really not to sweat it too much as that's still a low uptake level that close to treatment.

Hope that helps, and you're most welcome

Eric