The total radiation exposure during a CT scan depends on the region of the body under examination. A CT scan may expose the patient to the radiation equivalent of 100-800 chest x-rays. Some examples of CT scans and approximate exposures are:
Head CT: 2.0 mSv (200 mrem)
Chest CT: 8.0 mSv (800 mrem)
Abdomen CT: 10 mSv (1,000 mrem)
Pelvis CT: 10 mSv (1,000 mrem)
Don’t know what mSv or mrem means? See EPA’s Radiation Terms and Units webpage.