Calm down. You are going to drive yourself crazy! Are you also going to start to track the amount of radiation you get when you fly in an airplane too, and then stop taking vacations to other countries to minimize your radiation dose? At the low doses of radiation a CT scan uses, your risk of developing cancer from it is so small that it cannot be reliably measured. Because of the possibility of an increased risk, however, the American College of Radiology advises that no imaging exam be done unless there is a clear medical benefit.
Rather than focusing on tracking CTDI's and DLP's, which only a medical physicist would know how to interpret, you should put more of your effort into making sure the test is clinically indicated and protocolled correctly.
Example #1: You listed above that you had a CT chest with and without contrast, which is essentially a double CT (once without contrast and once with contrast). In most instances, CT chest is performed only without contrast. There are some exceptions, however. If you your doctor wanted to rule out pulmonary embolism or aortic dissection, he/she might order CT chest with contrast. There are very rare instances when CT chest with and without contrast is ordered, such as evaluating aorta for intramural hematoma (better seen without contrast) as well as aortic dissection (better seen with contrast).
Example #2: You listed above that you had a CT abdomen/pelvis with contrast. In most cases, CT abdomen/pelvis is performed only with contrast. There are some exceptions, however. If your doctor wanted to rule out renal stones, he/she might order CT abdomen/pelvis without contrast. Alternatively, if your doctor wanted to characterize a lesion in the liver, pancreas, or kidneys, he might order CT abdomen with and without contrast.
Example #3: Sometimes, a clinical question can be answered just as well or even better by MRI. For example, characterization of a lesion in the liver, pancreas, or kidneys can be characterized on MRI, which has no radiation.
I think you mean mSv not smv. According to the web site you referenced above, you have very very very minimal additional cancer risk (less than 0.5%), so basically nothing to worry about in the grand scheme of things (according to that same web site, the lifetime risk of dying in a motor vehicle accident is about 1%). As I mentioned before, if you and your doctor feel the test is necessary and appropriate, you should do the test.
Actually I was admitted in ER. I requested the doctor to do since i have some weird symptoms , I thought the doctor will do only head and neck , but they did the CTA blood vessel test.
The mSv is coming around 58 and not 42 mSv.
I plugged in 58 mSV into xrayrisk.com and your additional cancer risk is still less than 0.5%.
You need to stop worrying about this so much. The amount of weight you are giving this is not good for your mental health and well being. While there is a small risk (emphasis on small), there is a risk to everything you do in life. When you drive a car, you might crash. When you go swimming, you might drown. When you step outside, you might get hit by lightning. But it does not mean you are going to stop doing any of those activities. In all likelihood, you will still probably die of cancer (or heart disease), but that does not necessarily mean getting that extra CT or so was the main thing that caused it.
I agree with Chin_C. He touched most, if not all, of the bases correctly.
What I will tell you is that of several brilliant radiologists I have questioned in the past 10 years (I have had enormous amounts of radiation re Stage 4 cancer) regarding how much is too much, and how do you know when you're near or close to the max, each of them said there is NO absolute maximum that one can go by.
They all agreed that the less radiation one has, the better. However, had I missed certain studies, or been lax for whatever reason, even contradicting docs/oncologists who were "taking care of me," I'd have been dead from cancer probably 16-18 years ago.
The point is you're not having this radiation for fun, and you should not worry about its accumulation. The radiation you get may be saving you in ways you can't recognize.
Good luck. Try not to worry.