A. CT-Scan
B. Ultrasound
C. MRI
D. X-Ray
Explanation:
Most of the increased exposure in the United States is due to CT scanning and nuclear imaging, which require larger radiation doses than traditional x-rays. A chest x-ray, for example, delivers 0.1 mSv, while a chest CT delivers 7 mSv (see the table) — 70 times as much.