Nodules in different place on different scan?

I need to know whats up with the results of the scans. On one scan both nodules are in the lower part of each lobe one on right and one on left. On body scan i had done one is listed in the lower lobe but the other is listed in the upper lobe. What is up with this? Would there be a reason that the nodule changed places? Both scans only list 2 nodules both scans have the nodules listed pretty much same size. This is very strange to me. I plan on questioning my dr about this next week.

two more questions

1. Should I request a pet scan I had a cat scan with radiocontrast which located the nodules they were looking for pulmonary embolism but found these instead?

2. If i get my xrays from before will these 6mm nodules be noticable on the films or not?