Comparing Radiation Doses For Different Tests*
Imaging Test | Approximate Number of Chest X-Rays Needed to Get the Same Dose | Approximate Environmental Exposure Equivalent to the Dose† |
|---|---|---|
Single view chest x-ray (from back to front) | 1 | 10 days |
10 | 25 days | |
An x-ray series of the lumbar spine | 75 | 180 days |
CT of the head | 100 | 243 days |
CT of the abdomen/pelvis | 300–400 | 2–2.7 years |
Coronary artery angiography during cardiac catheterization | 350–750 | 2.3–4.9 years |
* These doses account for how much radiation is delivered and how susceptible the body part exposed to radiation is to radiation damage. | ||
† People are exposed constantly to low levels of naturally occurring radiation but the amount varies in different geographic locations. | ||
CT = computed tomography. | ||