Quantitative assessment of image quality (N = 64 subjects)
| MBIR | ASiR | Difference (MBIR-ASiR) | |||||
|---|---|---|---|---|---|---|---|
| Mean | (95% CI) | Mean | (95% CI) | Mean | (95% CI) | P Valuea | |
| Level 1 (angle of mandible) | |||||||
| Mean of IJV (HU) | 130.3 ± 19.6 | (125.4–135.1) | 131.0 ± 19.2 | (126.2–135.8) | −0.7 ± 2.7 | (−1.4 to −0.1) | .030 |
| Mean of SCM (HU) | 62.9 ± 5.0 | (61.7–64.2) | 64.4 ± 4.9 | (63.2–65.6) | −1.5 ± 2.2 | (−2.0 to −0.9) | <.001 |
| Mean of fat (HU) | −81.4 ± 23.2 | (−87.2 to −75.6) | −77.1 ± 23.3 | (−82.9 to −71.3) | −4.2 ± 8.1 | (−6.3 to −2.2) | <.001 |
| SD of IJV (HU) | 6.3 ± 2.6 | (5.7–7.0) | 7.3 ± 2.0 | (6.8–7.8) | −1.0 ± 1.9 | (−1.5 to −0.6) | <.001 |
| SD of SCM (HU) | 6.6 ± 1.4 | (6.3–7.0) | 7.1 ± 1.6 | (6.7–7.5) | −0.5 ± 1.5 | (−0.8 to −0.1) | .020 |
| SD of air (BN) (HU) | 6.3 ± 9.2 | (4.0–8.6) | 7.8 ± 9.2 | (5.5–10.1) | −1.5 ± 4.8 | (−2.7 to −0.3) | .016 |
| SNR of SCM | 16.2 ± 7.2 | (14.4–18.0) | 12.1 ± 4.3 | (11.0–13.2) | 4.1 ± 5.7 | (2.7–5.5) | <.001 |
| CNR of IJV and SCM | 7.6 ± 2.6 | (7.0–8.3) | 6.8 ± 2.4 | (6.2–7.4) | 0.9 ± 1.4 | (0.5–1.2) | <.001 |
| Lower level 2 (superior mediastinum) | |||||||
| Mean of SVC (HU) | 119.8 ± 24.5 | (113.7–125.9) | 117.8 ± 23.7 | (111.8–123.7) | 2.0 ± 7.3 | (0.2–3.9) | .030 |
| Mean of PM (HU) | 55.6 ± 11.0 | (52.9–58.4) | 53.3 ± 13.0 | (50.1–56.5) | 2.3 ± 7.9 | (0.4–4.3) | .021 |
| Mean of fat (HU) | −101.3 ± 19.4 | (−106.2 to −96.5) | −98.9 ± 18.1 | (−103.4 to −94.3) | −2.5 ± 7.7 | (−4.4 to −0.6) | .012 |
| SD of SVC (HU) | 10.2 ± 4.5 | (9.1–11.3) | 13.7 ± 4.9 | (12.5–14.9) | −3.5 ± 2.8 | (−4.2 to −2.8) | <.001 |
| SD of PM (HU) | 8.5 ± 2.4 | (7.9–9.1) | 10.9 ± 2.9 | (10.2–11.6) | −2.4 ± 3.0 | (−3.2 to −1.7) | <.001 |
| SD of air (BN) (HU) | 32.1 ± 32.5 | (23.9–40.2) | 33.5 ± 30.5 | (25.9–41.1) | −1.4 ± 23 | (−7.1–4.2) | .61 |
| SNR of PM | 6.9 ± 8.1 | (4.9–9.0) | 3.9 ± 3.4 | (3.0–4.7) | 3.1 ± 6.4 | (1.5–4.7) | <.001 |
| CNR of SVC and PM | 4.9 ± 2.0 | (4.4–5.4) | 3.7 ± 1.6 | (3.3–4.1) | 1.2 ± 1.3 | (0.9–1.5) | <.001 |
Note:—IJV indicates internal jugular vein.
↵a Paired t test.