Comparison of doses
We are exposed to naturally occurring radioactivity from the earth and the universe on a daily basis.
Comparative table
The table below compares:
- the doses of radiation associated with some medical imaging examinations,
- with doses of naturally occurring radioactivity.
Indicative table
This table is for information purposes only: with developments in the techniques used, these doses may change. Generally speaking, these developments will result in lower doses.
When imaging departments use modern equipment correctly, the doses from a CT scan can be divided by 10.
| Source of radiation | Duration of natural exposure required to reach an equivalent dose | |
|---|---|---|
| Everyday activities
|
4 hours as a passenger on a plane. The radiation is linked to the higher altitude and thinner atmosphere | 1 day |
| 7 days skiing in the mountains | 1 day | |
| X-ray radiography | Abdominal X-ray | 3 months |
| Pelvic X-ray | 4 months | |
| X-ray of the lumbar spine ¦ Front view | 2 months | |
| X-ray of the lumbar spine ¦ Full examination | 3.5 months | |
| X-ray of the lumbar spine ¦ Side view | 14 months | |
| Chest X-ray: Front view | 3 days | |
| Chest X-ray ¦ Side view | 10 days | |
| Chest X-ray ¦ Front view lying down | 3 days | |
| Scanner ¦ CT scan | CT scan of the abdomen | 4 years |
| CT scan of the lumbar spine | 4 years | |
| CT scan of the head | 8 months | |
| CT scan of the sinuses | 1 month | |
| CT scan of the lungs | 21 months | |
| Nuclear medicine |
Skeletal scan | 19.5 months |
| Thyroid examination | 3 to 9 months | |
| Lung perfusion scan | 9 months | |
| Brain perfusion scan | 20 months | |
| Kidney examination | 5 to 6.5 months | |
| Gastric reflux examination | 2 months | |
| Bile-duct scan | 11 months | |
| Myocardial perfusion scan | 15.5 to 26 months | |
| Ventricular function scan | 19 months | |
| PET scan | 22 months | |
| Dentistry | 2 ordinary teeth X-rays |
1 day |
Full jaw X-ray ¦ Orthopantomogram - Panoramic view |
1 day | |
| Cone Beam CT scan |
2 to 20 days |
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