Table 2.
Common carotid artery properties as determined by single and multiple M-line approaches.
| Single M-line | Multiple M-line | p-value | |||
|---|---|---|---|---|---|
| Carotid diameter | Diameter (mm) | 7.79 ± 0.91 | 7.80 ± 0.90 | 0.34 | |
| Intra-subject | SD (mm) | 0.19 (0.18–0.20) | 0.17 (0.16–0.18) | <0.001 | |
| CV (%) | 2.5 (2.4–2.6) | 2.2 (2.1–2.3) | |||
| Between subject | SD (mm) | 0.90 (0.87–0.92) | 0.89 (0.86–0.91) | ||
| CV (%) | 11.5 (11.2–11.8) | 11.4 (11.1–11.7) | |||
| Composite (nrep = 3) | SD (mm) | 0.90 (0.88–0.93) | 0.89 (0.87–0.92) | ||
| CV (%) | 11.6 (11.3–11.9) | 11.5 (11.2–11.8) | |||
| Carotid IMT | IMT (mm) | 0.86 ± 0.20 | 0.85 ± 0.18 | 0.07 | |
| Intra-subject | SD (mm) | 0.10 (0.10–11) | 0.07 (0.06–0.07) | <0.001 | |
| CV (%) | 11.9 (11.6–12.3) | 7.9 (7.6–8.2) | |||
| Between subject | SD (mm) | 0.18(0.17–0.19) | 0.17 (0.17–0.18) | ||
| CV (%) | 21.2 (20.1–22.0) | 20.4 (19.4–21.2) | |||
| Composite (nrep = 3) | SD (μm) | 0.19 (0.18–0.20) | 0.18 (0.17–0.19) | ||
| CV (%) | 22.3 (21.8–23.5) | 20.9 (20.2–21.9) | |||
| Carotid distension | Distension (μm) | 389 ± 132 | 385 ± 128 | <0.001 | |
| Intra-subject | SD (μm) | 39 (37–40) | 36 (35–37) | <0.001 | |
| CV (%) | 10.0 (9.6–10.3) | 9.4 (9.0–9.7) | |||
| Between subject | SD (μm) | 129 (125–132) | 126 (122–129) | ||
| CV (%) | 33.2 (32.3–34.0) | 32.7 (31.8–33.5) | |||
| Composite (nrep = 3) | SD (μm) | 131 (127–134) | 127 (123–131) | ||
| CV (%) | 33.7 (33.0–34.7) | 33.1 (32.4–34.1) | |||
| Carotid distensibility coefficient | DC (1/MPa) | 15.3 ± 5.5 | 15.2 ± 5.3 | <0.001 | |
| Intra-subject | SD (1/MPa) | 1.67 (1.61–1.72) | 1.55 (1.49–1.60) | <0.001 | |
| CV (%) | 10.9 (10.5–11.2) | 10.2 (9.9–10.6) | |||
| Between subject | SD (1/MPa) | 5.32 (5.15–5.47) | 5.17 (5.00–5.31) | ||
| CV (%) | 34.8 (33.8–35.6) | 34.2 (33.2–35.0) | |||
| Composite (nrep = 3) | SD (1/MPa) | 5.41 (5.24–5.55) | 5.24 (5.07–5.38) | ||
| CV (%) | 35.4 (34.7–36.5) | 34.7 (34.0–35.8) | |||
| Carotid YEM | YEM (MPa) | 0.70 ± 0.33 | 0.71 ± 0.30 | 0.90 | |
| Intra-subject | SD (MPa) | 0.19 (0.18–0.20) | 0.15 (0.13–0.16) | <0.001 | |
| CV (%) | 26.5 (24.7–27.9) | 20.5 (18.7–21.8) | |||
| Between subject | SD (MPa) | 0.32 (0.30–0.33) | 0.29 (0.28–0.30) | ||
| CV (%) | 44.4 (41.8–46.3) | 41.0 (39.5–42.2) | |||
| Composite (nrep = 3) | SD (MPa) | 0.34 (0.32–0.35) | 0.30 (0.29–0.32) | ||
| CV (%) | 46.9 (45.6–50.1) | 42.6 (41.9–44.7) |
Values are expressed as mean ± SD. p-value based on paired sample t-test. Reproducibility statistics are presented that includes the 25–75% CI (obtained using bootstrapping) between parentheses. SD, standard deviation; CV, coefficient of variation; IMT, intima-media thickness; YEM, young's elastic modulus; DC, distensibility coefficient.