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Patient Dose information

Typical effective doses, equivalent periods of natural background radiation and lifetime fatal cancer risks from diagnostic medical exposures

Diagnostic procedure Typical effective doses (mSv) Equivalent period of natural background radiation 1 Lifetime additional risk of fatal cancer per examination 2
X-ray examinations:
Limbs and joints (except hip) < 0.01 < 1.5 days 1 in a few million
Teeth (single bitewing) < 0.01 < 1.5 days 1 in a few million
Teeth (panoramic) 0.01 1.5 days 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
Nuclear medicine studies:
Lung ventilation (Kr-81m) 0.1 2.4 weeks 1 in 200,000
Lung perfusion (Tc-99m) 1 6 months 1 in 20,000
Kidney scan (Tc-99m) 1 6 months 1 in 20,000
Thyroid scan (Tc-99m) 1 6 months 1 in 20,000
Bone scan (Tc-99m) 4 2 years 1 in 5000
Dynamic cardiac (Tc-99m) 6 2.7 years 1 in 3300
Myocardial perfusion (Tl-201) 18 8 years 1 in 1100

1. UK average = 2.2mSv per year: regional averages range from 1.5 - 7.5 mSv per year

2. Approximate lifetime risk for patients 16 - 69 years old: for paediatric patients multiply risks by about 2 for geriatric patients divide risks by about 5


Last reviewed: 4 September 2008