Final answer:
A CT scan exposes only the portions of the patient's body that are being examined to radiation, where the doses are controlled to ensure safety, with the surrounding tissues receiving minimal scatter radiation.
Step-by-step explanation:
During a CT scan, x-rays are passed through the body to create detailed images of internal structures. Only the selected portions of the patient that are being scanned receive radiation exposure. The process involves taking multiple cross-sectional x-ray images, or slices, which a computer then processes to construct a three-dimensional representation of the area being examined. The amount of radiation used is carefully controlled and optimized to ensure the lowest possible dose necessary to achieve a quality image. Still, it is important to consider the risk versus benefit of radiation exposure. Diagnostic doses from CT scans are limited, with typical doses ranging up to about 10 mSv, and precautions are taken to expose only the tissue being imaged. The surrounding tissues receive some scatter radiation, but the amount is significantly less and efforts are made to minimize this exposure.