This really comes down to a matter of the risk of radiation exposure compared with the benefit of finding new pulmonary emboli (PE). For more specific information about the risk versus the benefit, please check with the radiologist responsible for radiation safety at the location where you would have this testing done. This would be the best specialist to answer your question of excessive radiation from 3 to 4 CT scans per year. Also ask your husband
Within a 2 year period time, approx. every 3-4 months i had ct scans on my lungs to see if the MAC bacteria was disappearing.
I asked my pulm. in Boston here if that was too much radiation, and he said having a ct scan is the same radiation pilots get flying to Europe. I guess that put it into perspective.
I haven't had one in a couple years, and if you don't NEED to have one i wouldn't, but if your doctor feels it's necessary to monitor his health i wouldn't hesitate.
lisa