Too much exposure to this form of
radiationCystitis - noninfectious
Radiation therapy can be harmful, but it's important to keep the risks of x-rays in perspective.
We're constantly being exposed to natural
radiationCystitis - noninfectious
Radiation therapy from the environment (from the earth, through cosmic rays from outer space). For example, a four-hour airline flight will expose you to the same amount of
radiationCystitis - noninfectious
Radiation therapy (from cosmic rays) as from a simple chest X-ray. This is the same as the amount of radiation we would be exposed to naturally (from background radiation) over 10 days. These days, X-ray pictures can be produced from very small doses of radiation, which helps minimise the risk of developing cancer as much as possible.
I took the following numbers from www.radiologyinfo.org/en/safety/index.cfm?pg=sfty_xray&bhcp=1 ; which compares some of the tests you had to the equivalent exposure from natural radiation:
Chest xray: Comparable to natural background radiation for 10 days
Chest CT: Comparable to natural background radiation for 3 years
Head CT: Comparable to natural background radiation for 8 months
CT Spine: Comparable to natural background radiation for 3 years
There is no doubt that you have had a lot of testing, and a larger dose of radiation exposure from Xrays and CTs than many people will have in a lifetime. That being said, in the grand scheme of things, this round of tests likely increases your risk of cancer very minimally. I would try not to spend energy worrying about it, as there is nothing that can be done after the fact. The benefits of having these tests to rule out serious problems generally far outweighs the risk. MRI doesn't cause radiation exposure, so that is one less thing to factor in.
I can't give you a time period for which you should avoid further Xrays/CTs. I think you should be sure to discuss with your doctor whether the tests in the future are necessary if any are suggested. Unfortunately, in such a litigious society, excessive testing is often done because physicians fear malpractice issues. If you have something potentially serious going on though, I think the benefits of getting the testing you need will usually outweigh the risks.
I hope this helps.
JMK MD