How accurate is ct with contrast for lung cancer detection?

It is very accurate: Ct scans are the best way to detect early lung cancers. No test is perfect but cancers slightly smaller than 1cm can be found.

See answer: Pulmonary ct is extremely sensitive in identifying lung nodules. When found, these nodules then need to be appropriately evaluated either with followup lung ct, pet-ct, or direct tissue sampling. Your clinical dr. Can best advise you – or you can be seen at a dedicated lung nodule center.