It's fairly standard to not do another CT. Part of the reason may be radiation based but a lot of it is based on it just not being medically necessary. It's unusual for a clot to not resolve by the time you come of anticoagulants.

A CT is 200-300 times more radiation than an x-ray, according to Consumer Reports. Also, there have been a lot of studies done recently showing that too many patients are getting exposed to too much unnecessary radiation. A repeat CT before going off warfarin would count as unnecessary.

I've had a number of CTs because of both PEs and because of sinus issues. There is a point where you really start to wonder if you want to run your brain under yet *more* radiation. At this point, I try to limit radiation exposure if it isn't absolutely necessary and I have turned down even simple x-rays that aren't diagnostic.

Also, there aren't that many patients that get a repeat CT unless there's something that is an actual acute problem. I had a repeat at five weeks after diagnosis because I'd developed pain and exhaustion, and etc ... none of which I had at the time I was diagnosed. They did a repeat (which, in retrospect, really wasn't necessary) and my clots were totally gone. Nothing about my treatment changed though...

At six months, most clots are considered "resolved." That can mean one of two things: either the clot is gone or the clot has somewhat solidified and become part of the vein wall (like a scar). Either way, you're not in danger any more and they'd rather not expose you to the radiation if it won't affect whether you come off the warfarin or not. It really is pretty common to not get the repeat CT. There are patients that get it, but it really depends on the person and their doctor.

As Toss said above, the radiation exposure from a CT scan are very significant. Everyone's situation is different, but when I was deciding whether to get a CT scan at the end of my six months on warfarin, I read that getting one exposes you to the equivalent radiation level of standing in modern-day Chernobyl for one hour. Between that and the fact that I had no symptoms and it was assumed my clot was dissolved, I did not get a scan at the six-month mark. Three years later, I'm doing fine and glad I didn't get scanned.

I talked with my doctor about doing a follow-up CT scan 6 months after my PE. I chose not to have one. I had no troubling symptoms, everything seemed to be healing well. I wanted to limit my radiation exposure as well as my medical bills. Also, I was being a bit cynical, or maybe just realistic. I knew there was a good chance that down the road I would have symptoms that worried me, and would need a CT then. I was right, and ended up having a CT 3 months later. So I am definitely in favor of saving CT scans until they are needed.

Yeah I'm not one to be over paranoid about CT scans; it's just that a test should make sense to have, weighing the risk vs the benefits.

Thank you everyone for your responses. This certainly makes me feel more comfotable with my docs advice. It makes sense logically that if the ultrasound on the leg shows up well that there is really no need to submit your body to radiation. So much of this treatment really seems like guesswork, and from what I have read many of us aeem to have differing symptoms and pains, etc. I guess it is the fear of the unknown that really gets your mind racing.