Don’t worry , you are not at high risk of cancer because of the radiation from that single CT scan . Cancer risk from radiation is not having a particular cut-off for avoiding risk of cancer , the more you are exposed to radiation the probability of cancer . But all our routine investigation and test using radiation have designed keeping in mind to minimise the exposure to as low as possible . Also investigation with radiation exposure are done only the benefit from that investigation outweigh the risk . So only think you need to keep in mind is - do investigation only when advised by a qualified medical practitioner . The avg exposure is about 10 mSv , which is higher than a normal person would have exposed in daily life , but will not be enough for causing any cancer in normal circumstances , so you don’t need to worry about a single CT exposure.