Radiation Dose to Adults From Common Imaging Examinations Procedure Approximate effective radiation dose Comparable to natural background radiation for ABDOMINAL REGION Computed Tomography (CT) — Abdomen and Pelvis 10 mSv 3 years Computed Tomography (CT) — Abdomen and Pelvis, repeated with and without contrast material 20 mSv 7 years Computed Tomography (CT) — Colonography 6 mSv 2 years Intravenous Pyelogram (IVP) 3 mSv 1 year Barium Enema (Lower GI X-ray) 8 mSv 3 years Upper GI Study With Barium 6 mSv 2 years BONE Spine X-ray 1.5 mSv 6 months Extremity (hand, foot, etc.) X-ray 0.001 mSv 3 hours CENTRAL NERVOUS SYSTEM Computed Tomography (CT) — Head 2 mSv 8 months Computed Tomography (CT) — Head, repeated with and without contrast material 4 mSv 16 months Computed Tomography (CT) — Spine 6 mSv 2 years CHEST Computed Tomography (CT) — Chest 7 mSv 2 years Computed Tomography (CT) — Lung Cancer Screening 1.5 mSv 6 months Chest X-ray 0.1 mSv 10 days DENTAL Dental X-ray 0.005 mSv 1 day HEART Coronary Computed Tomography Angiography (CTA) 12 mSv 4 years Cardiac CT for Calcium Scoring