Table 3.
Comparison in objective image quality among radiation dose levels in iterative reconstruction (IR) and filtered back projection (FBP)
| TV (kV) | TC (mA) | CNR for less attenuated nodules (−800 HU) |
CNR for more attenuated nodules (−630 HU) |
||
|---|---|---|---|---|---|
| IR | FBP | IR | FBP | ||
| 120 | 10 | 1.97 ± 1.32 | 0.98 ± 0.40 | 0.96 ± 0.30 | 0.61 ± 0.30 |
| 120 | 20 | 2.07 ± 0.76 | 1.07 ± 0.26 | 1.04 ± 0.35 | 0.63 ± 0.34 |
| 120 | 80 | 2.67 ± 1.46 | 1.41 ± 0.67 | 1.22 ± 0.32 | 0.71 ± 0.37 |
| 120 | 160 | 3.05 ± 1.80 | 1.66 ± 0.73 | 1.54 ± 0.67 | 0.96 ± 0.37 |
| 100 | 80 | 2.52 ± 1.46 | 1.23 ± 0.52 | 1.09 ± 0.37 | 0.69 ± 0.30 |
| 80 | 320 | 3.02 ± 1.35 | 1.63 ± 0.63 | 1.23 ± 0.38 | 0.75 ± 0.35 |
| p-value | 0.337 | 0.624 | 0.742 | 0.301 | |
CNR, contrast-to-noise ratio; HU, Hounsfield units; TC, tube current; TV, tube voltage.