Should I worry about amount of radiation from a CT scan for a pulmonary embolism study?

Radiation concern. It is always reasonable to be concerned about radiation exposure, but you have to keep it in perspective of the risk of the disease being considered. One ct scan is not a lot of radiation, while a pulmonary embolism can cause death. The risk to benefit would favor having the ct scan.
No. I'd worry more about possible pulmonary embolism which could be deadly in the short-term as opposed to excess radiation from the ct scan which would need to be repeated excessively in order to be worrisome in the long term. I suppose if the tech wasn't paying attention and the ct scanner hadn't been checked & certified, it's possible to get too much radiation but i'm more worried about pe.
No. As drs. White, lessnau, and lin all said, you risk of having an undetected and untreated pulmonary embolism is far higher than your risk from having one ct scan of your lungs.