Hi, I have a technical question for a radiologist, as to whether a CT scan WITH contrast is really needed in this situation: I m an anesthesiologist. My wife had a laparoscopic fenestration of a benign 12x12x10 cm liver cyst 10 days ago. One night in hospital then home, normal post op course. She has been slightly short of breath with normal activity, feels it is hard to take a deep breath. No fever. I was concerned about the possibility of a post op pulmonary embolus, so I contacted her family practitioner. (surgeon is in a city 250 miles away). He wanted to get a CT scan with contrast, but on a previous CT with contrast several years ago she had a reaction of nearly passing out after the contrast was given, so he decided not to get a CT. Chest Xray was normal. The D-dimer test was elevated (I understand it usually is post-op). Ultrasound of liver shows no hematoma and looks like normal post op changes, and ultrasound of legs shows no DVT. Is it reasonable to conclude PE is unlikely? She is still worried and wondering if she should attempt a CT with contrast, even though the idea of getting contrast REALLY frightens her. Thanks, in advance, for your thoughts. RF