Table 6.
Highest sample size required for three- or one-region approach for helical chest protocol performed on 16-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 | 2896(2392) | 724(598) | 322(266) | 181(150) | 116(96) | 81(67) | 60(49) | 46(38) | 36(30) | 29(24) | 24(20) | 21(17) | 18(15) | 15(13) | 13(11) |
| 5 | 164(91) | 41(23) | 19(11) | 11(6) | 7(4) | 5(3) | 4(2) | 3(2) | 3(2) | 2(1) | 2(1) | 2(1) | 1(1) | 1(1) | 1(1) |
| 10 | 25(17) | 7(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) |
| 15 | 11(8) | 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(1) |
| 20 | 6(4) | 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) |
| 50 | 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) | 1(1) |