Table 1.
Average Stone Size Determined by CT and S-Mode US
| Size group | No. of stones | CT size (mm) | S-mode US stone size (mm) | Differencea(mm) | Bias ±95% CI | pb |
|---|---|---|---|---|---|---|
| All stones | 93 | 5.0 ± 2.7 | 5.6 ± 2.0 | 1.4 ± 1.3 | 0.58 ± 0.38 | 0.0028 |
| ≤5 mm | 59 | 3.4 ± 0.8 | 4.7 ± 1.5 | 1.5 ± 1.0 | 1.24 ± 0.35 | <0.0001 |
| 5–10 mm | 29 | 6.7 ± 1.4 | 6.5 ± 1.2 | 1.0 ± 0.7 | 0.29 ± 0.46 | 0.19 |
| >10 mm | 5 | 12.9 ± 3.7 | 10.7 ± 2.3 | 3.0 ± 3.7 | −2.17 ± 3.88 | 0.27 |
a
Difference represents average absolute difference between CT and S-mode size measurements.
b
p > 0.05 is significant for no bias; nonsignificance is also dependent on sample size.
US = ultrasound.