How many times can CT scans be performed?

Ionizing radiation has been confirmed to cause cancer. However, CT scans have become an essential tool in current medical practices and help improve the quality of healthcare. No upper or lower limits have been decided. Therefore, medical practitioners must be responsible for deciding which examinations are medically necessary for given objectives. The basic rule for medical radiation protection is to only use the necessary amount of exposure for the people that need radiation. Given that rule, the medical practitioner must determine what medical care to provide based on an awareness that they have the final responsibility for managing patient exposure levels. (For more information about radiation effects on people, see also the explanation in the response to question "To what extent does radiation cause cancer?" in Chapter 3.)