Can A CT Scan Detect Diverticulitis If The Tech Had

Can a CT scan detect diverticulitis if the tech had me put my legs up. I was diagnosed with diverticulitis about a month ago and I had a CT scan done, but they had me lay flat on my back and not put my legs up. I was back in the ER with the same pain but they said that the CT did not show anything and I feel they r wrong. I am scheduled to have surgery later this month because the first scan showed a perforation.