Comparing Radiation Doses For Different Tests*
Comparing Radiation Doses For Different Tests*
Imaging Test |
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 |
2.4 days |
|
20 |
48 days |
|
|
An x-ray series of the lumbar spine |
75 |
180 days |
|
CT of the head |
100 |
243 days |
|
CT of the abdomen |
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. |
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† People are exposed constantly to low levels of naturally occurring radiation but the amount varies in different locations. |
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CT = computed tomography. |