Table 4. Comparison of measured VCE, TID, radiation dose, quantitative and qualitative image analysis.
| Parameters | Group 2 | Reference Group | P value |
|---|---|---|---|
| Measured VCE (HU) | 393.5±33.0 | 465.0±50.8 | 0.0001* |
| TID (g) | 19.5±2.7 | 28.7±1.4 | 0.0001* |
| HE (mSv) | 4.8±0.8 | 7.8±2.0 | 0.0001* |
| Quantitative image quality analysis | |||
| Image noise (HU) | 26.0±4.5 | 24.6±3.3 | 0.070 |
| SNR | |||
| RCA | 15.1±2.9 | 19.1±4.0 | 0.0001* |
| LM | 15.9±3.4 | 19.0±3.3 | 0.0001* |
| LAD | 15.9±3.0 | 18.1±3.5 | 0.001* |
| LCx | 15.6±2.9 | 18.2±3.8 | 0.001* |
| CNR | |||
| RCA | 12.1±2.6 | 16.4±3.7 | 0.0001* |
| LM | 12.9±2.6 | 16.4±3.0 | 0.0001* |
| LAD | 12.7±2.4 | 15.4±3.2 | 0.0001* |
| LCx | 12.6±2.6 | 15.6±3.5 | 0.0001* |
| FOM (mSv–1) | |||
| RCA | 33.1±17.9 | 38.8±19.8 | 0.201 |
| LM | 37.4±16.9 | 36.9±14.9 | 0.888 |
| LAD | 36.0±15.9 | 33.2±14.9 | 0.485 |
| LCx | 35.8±15.6 | 33.9±15.6 | 0.586 |
| Qualitative image quality analysis | |||
| VCE | |||
| RCA | 4.8 (4.0–5.0) | 4.9 (4.5–5.0) | 0.130 |
| LM | 4.7 (3.5–5.0) | 4.8 (4.0–5.0) | 0.186 |
| LAD | 4.7 (4.0–5.0) | 4.9 (4.0–5.0) | 0.169 |
| LCx | 4.8 (3.5–5.0) | 4.9 (3.5–5.0) | 0.191 |
*, P<0.05. CNR, contrast-to-noise ratio; FOM, figure of merit; HE, effective dose; SNR, signal-to-noise ratio; TID, total iodine dose; VCE, vessel contrast enhancement; LAD, left anterior descending; LCx, left circumflex; LM, left main; RCA, right coronary artery.