Table 1 Means (± SDs) and 95% CIs for the radiographic measurements of the absolute, averaged, and standardized values of vertical tracheal diameter (VTD) at caudal cervical, thoracic-inlet, and intra-thoracic tracheal regions for 80 non-bulldog brachycephalic small-breed dogs without evidence of pulmonary or cardiovascular disease
Variables | Mean ± SD | 95% CI | P-value < 0.05 | ||
|---|---|---|---|---|---|
Absolute vertical tracheal diameter (VTD)/mm | ANOVA test | Tukey’s test | Unpaired t-test | ||
Caudal cervical (A) VTD (mid-C5) | 10.8 ± 3.2 | 10.1–11.6 | A-B, p < 0.0001 | A-B, p < 0.0001 | |
Thoracic inlet (B) VTD (ca-C7) | 8.6 ± 3.0 | 7.9–9.2 | P = 0.0001 | A-C, p = 0.036 | A-C, p = 0.017 |
Intrathoracic (C) VTD (mid-T2-T3) | 9.5 ± 3.3 | 8.8–10.3 | B-C, p = 0.137 | B-C, p = 0.057 | |
Averaged VTD | 9.7 ± 3.2 | 8.9–10.4 | |||
Standardizing parameter/mm | |||||
Manubrium-length (ML) | 27.5 ± 8.4 | 25.6–29.3 | |||
Thoracic inlet-distance (Ti-D) | 48.6 ± 13.6 | 45.5–51.6 | |||
Proximal R3-width (PR3-W) | 3.1 ± 1.1 | 2.9–3.3 | |||
Manubrium-tracheal index (M-TI) | ANOVA test | Tukey’s test | Unpaired t-test | ||
M-TI (caudal cervical trachea, A) | 0.41 ± 0.10 | 0.39–0.43 | A-B, p < 0.0001 | ||
M-TI (thoracic inlet trachea, B) | 0.32 ± 0.07 | 0.30–0.33 | A-C, p < 0.0001 | ||
M-TI (intrathoracic trachea, C) | 0.35 ± 0.07 | 0.34–0.37 | B-C, p = 0.020 | ||
Averaged M-TI | 0.36 ± 0.08 | 0.34–0.38 | |||
Thoracic inlet-tracheal index (Ti-TI) | |||||
Ti-TI (caudal cervical trachea, A) | 0.23 ± 0.05 | 0.22–0.24 | A-B, p < 0.0001 | A-B, p < 0.0001 | |
Ti-TI (thoracic inlet trachea, B) | 0.18 ± 0.04 | 0.17–0.18 | P < 0.0001 | A-C, p < 0.0001 | A-C, p < 0.0001 |
Ti-TI (intrathoracic trachea, C) | 0.20 ± 0.04 | 0.19–0.20 | B-C, p = 0.006 | B-C, p ≤ 0.003 | |
Averaged Ti-TI | 0.20 ± 0.04 | 0.19–0.21 | |||
Proximal R3-tracheal score (PR3-TS) | |||||
PR3-TS (caudal cervical trachea, A) | 3.7 ± 0.9 | 3.5–3.9 | A-B, p < 0.0001 | ||
PR3-TS (thoracic inlet trachea, B) | 2.8 ± 0.7 | 2.7–3.0 | A-C, p < 0.0001 | ||
PR3-TS (intrathoracic trachea, C) | 3.2 ± 0.6 | 3.0–3.3 | B-C, p = 0.018 | ||
Averaged PR3-TS | 3.2 ± 0.7 | 3.1–3.4 | |||