Subjective image quality rating (1 = worst, 5 = best) for brain structures and intracranial hemorrhage for filtered back-projection and 5 strengths (S1–S5) of sinogram-affirmed iterative reconstruction technique
Image Reconstruction Technique | Rating Brain Structures | Rating Intracranial Hemorrhage | ||||||
---|---|---|---|---|---|---|---|---|
340 mAs | 260 mAs | 340 mAs | 260 mAs | |||||
κ | κ | κ | κ | |||||
FBP | 2.8 ± 0.4 | 0.71 | 2.0 ± 0.8 | 0.59 | 2.5 ± 0.7 | 0.9 | 2.1 ± 0.8 | 0.67 |
S1 | 3.5 ± 0.6a | 0.71 | 2.9 ± 0.6a | 0.48 | 3.15 ± 0.8c | 0.85 | 2.8 ± 0.8a,c | 0.9 |
S2 | 4.4 ± 0.6 | 0.77 | 3.7 ± 0.7a | 0.51 | 3.8 ± 0.7c | 0.82 | 3.4 ± 0.7c | 0.75 |
S3 | 4.5 ± 0.5c | 0.47 | 4.7 ± 0.5c | 0.62 | 4.39 ± 0.7c | 0.80 | 4.0 ± 0.7c | 0.72 |
S4 | 3.2 ± 0.7a,c | 0.86 | 3.4 ± 1.0a,c | 0.55 | 4.65 ± 0.6c | 0.81 | 4.65 ± 0.5c | 0.61 |
S5 | 2.0 ± 0.7b,c | 0.64 | 2.5 ± 0.9b,c | 0.37 | 4.44 ± 0.7c | 0.81 | 4.68 ± 0.6c | 0.55 |
↵Note:—a P > .05 when compared with standard FBP at 340 mAs;
↵b P > .05 when compared with FBP at 260 mAs;
↵c P > 0.1 when compared with the same image reconstruction technique at different tube current–time product.
Interobserver agreement (slight [κ < 0.3], moderate [κ = 0.3–0.7], good agreement [κ > 0.7]).