Diagnostic procedure

Typical effective dose (mSv)

Equivalent period of natural background radiation*

Risk of fatal cancer per examination**

X-ray examinations:

Limbs and joints (except hip)

<0.01

<1.5 days

1 in a few million

Teeth (single bitewing)
(panoramic)

<0.01

0.01

<1.5 days

1.5 days

1 in a few million

1 in 2 million

Chest (single PA film)

0.02

3 days

1 in a million

Skull

0.07

11 days

1 in 300,000

Cervical spine (neck)

0.08

2 weeks

1 in 200,000

Hip

0.3

7 weeks

1 in 67,000

Thoracic spine

0.7

4 months

1 in 30,000

Pelvis

0.7

4 months

1 in 30,000

Abdomen

0.7

4 months

1 in 30,000

Lumbar spine

1.3

7 months

1 in 15,000

Barium swallow

1.5

8 months

1 in 13,000

IVU (kidneys and bladder)

2.5

14 months

1 in 8000

Barium meal

3

16 months

1 in 6700

Barium follow

3

16 months

1 in 6700

Barium enema

7

3.2 years

1 in 3000

CT head

2

1 year

1 in 10,000

CT chest

8

3.6 years

1 in 2500

CT abdomen/pelvis

10

4.5 years

1 in 2000

Radionuclide studies:

Lung ventilation (^81mKr)

0.1

2.4 weeks

1 in 200,000

Lung perfusion (^99mTc)

1

6 months

1 in 20,000

Kidney (^99mTc)

1

6 months

1 in 20,000

Thyroid (^99mTc)

1

6 months

1 in 20,000

Bone (^99mTc)

4

2.3 years

1 in 5000

Dynamic cardiac (^99mTc)

6

2.7 years

1 in 3300

Myocardial perfusion (²⁰¹Tl)

18

8 years

1 in 1100