Table 7.
Highest sample size required for three- or one-region approach for abdomen–pelvis protocol performed on 320-row scanner, as a function of anticipated effective dose, precision, and desired confidence level. Sample sizes displayed are for confidence level of 95%, with sample sizes for 90% confidence level in parentheses.
| Precision | Anticipated effective dose (mSv) |
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (q [%]) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| 2 | 6727(5558) | 1682(1390) | 748(618) | 421(348) | 270(223) | 187(155) | 138(114) | 106(87) | 84(69) | 68(56) | 56(46) | 47(39) | 40(33) | 35(29) | 30(25) |
| 5 | 381(210) | 96(53) | 43(24) | 24(14) | 16(9) | 11(6) | 8(5) | 6(4) | 5(3) | 4(3) | 4(2) | 3(2) | 3(2) | 2(2) | 2(1) |
| 10 | 58(39) | 15(10) | 7(5) | 4(3) | 3(2) | 2(2) | 2(1) | 2(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) |
| 15 | 24(17) | 6(5) | 3(2) | 2(2) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) |
| 20 | 14(10) | 4(3) | 2(2) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) |
| 50 | 2(2) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) | 1(1) |