Table 3.
Organ and effective dose of the two patients from their CT examinations. Each patient underwent a combined chest-abdomen-pelvis (CAP) examination consisting of a chest scan and an abdomen-pelvis scan. Each dose value is the average over six tube starting angles. The percentage value in the bracket is the coefficient of variation (standard deviation×100%∕average) across tube starting angles.
| Dose (mGy) | Dose ratiob | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Newborn (5 weeks, female) | Teenager (12 years, male) | ||||||||||
| Chest | Abdomen-pelvis | CAPa | Chest | Abdomen-pelvis | CAPa | CAP | |||||
| Respiratory system | |||||||||||
| Pharynx-larynx | 1.86 | (5%)c | 0.23 | (1%) c d, d | 2.09 | 1.03 | (17%) c | 0.06 | (3%) c d, d | 1.09 | 1.9 |
| Trachea-bronchi | 3.28 | (0%) | 0.58 | (2%) c d, d | 3.86 | 3.88 | (3%) | 0.38 | (2%) c d, d | 4.26 | 0.9 |
| Lungs | 3.68 | (0%) | 3.54 | (3%) | 7.22 | 3.93 | (0%) | 2.54 | (2%) | 6.47 | 1.1 |
| Alimentary system | |||||||||||
| Esophagus | 3.20 | (0%) | 1.55 | (3%) c | 4.75 | 3.35 | (2%) | 1.37 | (1%) | 4.72 | 1.0 |
| Stomach | 1.36 | (7%) c | 6.36 | (0%) | 7.72 | 1.53 | (17%) c | 5.04 | (1%) | 6.57 | 1.2 |
| Pancreas | 0.34 | (2%) c d, d | 6.38 | (1%) | 6.72 | 0.55 | (4%) c d, d | 4.91 | (1%) | 5.46 | 1.2 |
| Liver | 2.02 | (8%) c | 6.56 | (0%) | 8.58 | 1.57 | (13%)c | 4.93 | (0%) | 6.50 | 1.3 |
| Gall bladder | 1.02 | (16%)c | 6.88 | (1%) | 7.90 | 0.37 | (9%)c d, d | 5.52 | (8%) | 5.89 | 1.3 |
| Small intestine | 0.27 | (4%) c | 7.07 | (0%) | 7.34 | 0.15 | (4%)c d, d | 5.57 | (1%) | 5.72 | 1.3 |
| Large intestine | 0.24 | (7%) c | 6.76 | (0%) | 7.00 | 0.10 | (3%) c d, d | 5.08 | (1%) | 5.18 | 1.4 |
| Circulatory system | |||||||||||
| Heart | 3.56 | (0%) | 4.16 | (7%) | 7.72 | 4.14 | (1%) | 2.61 | (10%) | 6.75 | 1.1 |
| Urogenital system | |||||||||||
| Kidneys | 1.52 | (8%) c | 6.08 | (0%) | 7.60 | 0.75 | (11%) c | 4.52 | (0%) | 5.27 | 1.4 |
| Urinary bladder | 0.04 | (3%) c d, d | 6.30 | (2%) | 6.34 | 0.02 | (2%) c d, d | 5.20 | (3%) | 5.22 | 1.2 |
| Prostate | - | - | - | 0.01 | (5%) c d, d | 4.05 | (2%) | 4.06 | - | ||
| Testes | - | - | - | 0.00 | (14%) c d, d | 5.10 | (15%) | 5.10 | - | ||
| Ovaries | 0.05 | (5%)c d, d | 6.28 | (2%) | 6.33 | - | - | - | - | ||
| Uterus | 0.04 | (2%) c d, d | 6.18 | (2%) | 6.22 | - | - | - | - | ||
| Vagina | 0.03 | (5%) c d, d | 6.24 | (2%) | 6.27 | - | - | - | - | ||
| Skeletal system | |||||||||||
| Bone surface | 1.81 | (2%) | 3.36 | (0%) | 5.17 | 1.45 | (1%) | 2.68 | (0%) | 4.13 | 1.3 |
| Red bone marrow | 0.83 | (1%) | 1.57 | (0%) | 2.40 | 1.01 | (1%) | 1.91 | (0%) | 2.92 | 0.8 |
| Integumentary system | |||||||||||
| Skin | 0.54 | (1%) | 1.70 | (1%) | 2.24 | 0.60 | (1%) | 1.24 | (0%) | 1.84 | 1.2 |
| Additional organs∕tissues | |||||||||||
| Brain | 0.12 | (1%) c d, d | 0.05 | (1%) c d, d | 0.17 | 0.07 | (2%)c d, d | 0.01 | (3%) c d, d | 0.08 | 2.1 |
| Eyes | 0.08 | (7%) c d, d | 0.03 | (2%) c d, d | 0.11 | 0.05 | (3%)c d, d | 0.01 | (8%) c d, d | 0.06 | 1.8 |
| Thyroid | 2.85 | (1%) | 0.36 | (3%) c d, d | 3.21 | 4.47 | (10%) | 0.23 | (2%) c d, d | 4.70 | 0.7 |
| Breasts | 2.88 | (1%) | 1.62 | (31%) c | 4.50 | 3.64 | (23%) | 1.04 | (42%) c | 4.68 | 1.0 |
| Thymus | 3.53 | (0%) | 0.73 | (3%) c | 4.26 | 4.05 | (4%) | 0.51 | (4%) c d, d | 4.56 | 0.9 |
| Spleen | 2.63 | (3%) | 5.79 | (1%) | 8.42 | 1.60 | (18%) | 4.60 | (1%) | 6.20 | 1.4 |
| Adrenal glands | 2.04 | (2%) | 6.05 | (0%) | 8.09 | 1.29 | (4%)c | 4.07 | (2%) | 5.36 | 1.5 |
| Residual soft tissues | 0.99 | (1%) | 2.81 | (1%) | 3.80 | 0.73 | (0%) | 1.44 | (0%) | 2.17 | 1.8 |
| Effective dose (mSv) | 1.64 | (1%) | 4.04 | (2%) | 5.68 | 1.78 | (5%) | 3.15 | (1%) | 4.93 | 1.2 |
Dose from the combined chest-abdomen-pelvis (CAP) examination, i.e., the summation of dose from the chest scan and that from the abdomen-pelvis scan.
Dose ratio equals dose to the newborn patient from her CAP examination over dose to the teenager patient from his CAP examination.
Organs completely outside of the image coverage (Table 1).
Organs completely outside of the scan coverage (scan coverage equals image coverage plus overranging distance, see Table 1).