How exactly does contrast for a pulmonary scan work? I believe to have had angor animi for 2 months after a pulmonary CAT scan in 1999. I had symptoms of pulmonary hypertension when I presented to the E.R. in Chicago that night and I am having a difficult time getting answers from my health care professionals. I had no history nor symptoms of "clots" at the time the CAT scan was ordered. I suspect foul play in the whole incident. Any information/articles about pulmonary CAT scans would be helpful.