Table 3.
Quantitative analyses of image noise and vascular and HCC Lesion Contrast-to-Noise Ratios (CNRs)
| QIR level | 0 | # | 1 | 2 | 3 | 4 |
|---|---|---|---|---|---|---|
| Late arterial | ||||||
| Noise (HU) | 29 (27–31) | 22 (20–24) | 19 (17–21) | 16 (14–18) | ||
| 27 (25–30) | 24 (22–26) | 21 (19–23) | 18 (17–20) | 15 (14–17) | ||
| 31 (29–32) | 24 (23–25) | 20 (20–22) | 17 (16–19) | 14 (13–16) | ||
| CNRvascular | 11 (6–18) | 14 (8–23) | 17 (10–26) | 19 (11–32) | ||
| 12 (6–20) | 14 (7–23) | 17 (9–26) | 19 (12–29) | 24 (13–38) | ||
| 9 (6–16) | 13 (8–20) | 15 (9–23) | 15 (10–26) | 22 (12–33) | ||
| CNRHCC | 2.8 (1.6–3.8) | 3.4 (2.1–4.5) | 4.1 (2.6–5.1) | 4.5 (3.0–6.2) | ||
| 3.0 (1.8–4.0) | 3.3 (2.0–4.5) | 3.6 (2.3–4.9) | 4.4 (2.7–5.5) | 5.1 (3.2–6.8) | ||
| 2.1 (1.3–3.2) | 2.7 (1.8–4.0) | 3.0 (2.0–4.6) | 3.6 (2.8–5.5) | 4.3 (2.8–6.5) | ||
| Portal venous | ||||||
| Noise (HU) | 29 (27–31) | 22 (21–24) | 19 (18–21) | 16 (15–18) | ||
| 28 (26–30) | 25 (23–27) | 22 (20–24) | 19 (17–20) | 16 (14–18) | ||
| 29 (27–32) | 23 (21–25) | 20 (18–22) | 16 (15–19) | 14 (13–16) | ||
| CNRvascular | 7 (5–8) | 8 (6–10) | 10 (7–12) | 11 (8–14) | ||
| 7 (5–9) | 8 (6–10) | 9 (7–11) | 11 (8–13) | 13 (10–16) | ||
| 6 (4–7) | 7 (6–9) | 8 (7–11) | 9 (8–12) | 11 (9–15) | ||
| CNRHCC | 1.4 (0.7–2.9) | 1.6 (0.8–3.6) | 1.9 (1.0–4.2) | 2.2 (1.0–4.9) | ||
| 1.6 (0.9–2.9) | 1.8 (0.9–3.2) | 2.1 (1.1–3.6) | 2.5 (1.3–4.2) | 2.9 (1.5–5.0) | ||
| 0.9 (0.5–2.6) | 1.1 (0.6–3.3) | 1.3 (0–7–3.8) | 1.5 (0.8–4.4) | 1.8 (1.0–5.1) | ||
| Delayed | ||||||
| Noise (HU) | 28 (27–31) | 22 (21–24) | 19 (18–21) | 16 (15–17) | ||
| 29 (26–30) | 25 (23–27) | 22 (20–24) | 19 (18–20) | 16 (14–17) | ||
| 29 (27–33) | 23 (21–26) | 20 (18–22) | 16 (16–19) | 13 (13–16) | ||
| CNRvascular | 2.2 (1.7–3.0) | 2.7 (2.1–3.8) | 3.2 (2.3–4.4) | 3.6 (2.8–5.2) | ||
| 2.3 (1.8–3.0) | 2.6 (2.0–3.3) | 2.9 (2.3–3.8) | 3.4 (2.5–4.4) | 4.1 (3.0–5.2) | ||
| 2.1 (1.5–3.0) | 2.7 (1.8–3.9) | 3.1 (2.1–4.2) | 3.6 (2.5–5.0) | 4.2 (3.0–6.0) | ||
| CNRHCC | 0.7 (0.3–1.3) | 0.9 (0.4–1.6) | 1.0 (0.4–1.8) | 1.2 (0.5–2.1) | ||
| 1.0 (0.4–1.4) | 1.1 (0.4–1.6) | 1.2 (0.5–1.8) | 1.3 (0.6–2.1) | 1.6 (0.6–2.4) | ||
| 0.5 (0.2–1.2) | 0.6 (0.2–1.4) | 0.7 (0.3–1.6) | 0.8 (0.3–1.8) | 0.9 (0.4–2.1) | ||
Values are medians with interquartile ranges in parentheses. For each, in the top line, the results for the total study population are reported. The middle and bottom lines depict the results for the populations scanned before and after the service pack installation