Table 2.
Comparison of quantitative image quality parameters for the noncontrast head CT series between ASiR-V and all three DLIR strength levels
| ASiR-V | DLIR-L | DLIR-M | DLIR-H | P value | |
|---|---|---|---|---|---|
| CT Attenuation (HU) | |||||
| Thalamic GM | 33.77 ± 2.44* | 34.13 ± 2.18 | 34.05 ± 2.03 | 33.95 ± 2.02 | 0.001 |
| PLIC WM | 24.69 ± 2.30*ab | 25.33 ± 2.03b | 25.43 ± 1.99b | 25.64 ± 1.99 | < 0.001 |
| M5 GM | 36.99 ± 2.10ab | 36.63 ± 2.04b | 36.50 ± 2.00b | 36.22 ± 1.97 | < 0.001 |
| CSO WM | 26.86 ± 2.17b | 27.04 ± 2.00 | 27.08 ± 1.88 | 27.17 ± 1.81 | 0.002 |
| Image noise (HU) | |||||
| Thalamic GM | 5.51 ± 1.16ab | 5.32 ± 1.11ab | 4.39 ± 0.92b | 3.46 ± 0.71 | < 0.001 |
| PLIC WM | 5.74 ± 1.25ab | 5.33 ± 1.02ab | 4.31 ± 0.85b | 3.23 ± 0.62 | < 0.001 |
| M5 GM | 5.05 ± 1.04ab | 4.87 ± 1.01ab | 4.04 ± 0.83b | 3.22 ± 0.72 | < 0.001 |
| CSO WM | 5.46 ± 1.04*ab | 5.10 ± 0.97ab | 4.07 ± 0.78b | 3.07 ± 0.58 | < 0.001 |
| PF (artifacts) | 8.85 ± 1.39*ab | 8.24 ± 1.02ab | 7.12 ± 0.99b | 5.94 ± 0.99 | < 0.001 |
| Air | 6.83 ± 0.92*ab | 4.75 ± 0.70ab | 3.55 ± 0.60b | 2.29 ± 0.50 | < 0.001 |
| ICH | 6.01 ± 1.58ab | 5.89 ± 1.62ab | 5.00 ± 1.46b | 4.23 ± 1.37 | < 0.001 |
| SNR | |||||
| Thalamic GM | 6.40 ± 1.37ab | 6.69 ± 1.43ab | 8.09 ± 1.68b | 10.22 ± 2.11 | < 0.001 |
| PLIC WM | 4.50 ± 1.05*ab | 4.93 ± 1.02ab | 6.13 ± 1.29b | 8.23 ± 1.68 | < 0.001 |
| M5 GM | 7.61 ± 1.51ab | 7.81 ± 1.52ab | 9.38 ± 1.79b | 11.74 ± 2.39 | < 0.001 |
| CSO WM | 5.11 ± 1.11*ab | 5.50 ± 1.14ab | 6.89 ± 1.36b | 9.15 ± 1.76 | < 0.001 |
| ICH | 10.44 ± 3.75ab | 10.73 ± 3.73ab | 12.68 ± 4.55b | 15.18 ± 5.72 | < 0.001 |
| CNR | |||||
| Thalamic GM-PLIC WM | 1.65 ± 0.47ab | 1.69 ± 0.44ab | 2.03 ± 0.51b | 2.53 ± 0.60 | < 0.001 |
| M5 GM-CSO WM | 1.95 ± 0.50ab | 1.95 ± 0.47ab | 2.35 ± 0.54b | 2.91 ± 0.65 | < 0.001 |
HU Hounsfield units, GM gray matter, WM white matter, PLIC posterior limb of the internal capsule, M5 M5 cortex region (lateral MCA territory) according to Alberta Stroke Program Early CT Score — ASPECTS, CSO centrum semiovale, PF posterior fossa, ICH intracranial hemorrhage, SNR signal-to-noise ratio, CNR contrast-to-noise ratio, ASiR-V adaptive statistical iterative reconstruction-Veo, DLIR-L deep learning–based image reconstruction low strength level, DLIR-M deep learning–based image reconstruction medium strength level, DLIR-H deep learning–based image reconstruction high strength level
Post hoc pairwise multiple comparisons procedure with the Dunn-Bonferroni test showed a statistically significant (P < 0.05) difference between means when compared with DLIR-L (*), DLIR-M (a), and DLIR-H (b)