Introduction
Materials and methods
Image quality phantoms
CT scanners and acquisition/reconstruction parameters
Manufacturer and model | Tube voltage [kV] | ATCM | Pitch b | Rotation time [s] d | Collimation [mm] | Slice thickness / increment f | Reconstruction algorithm/kernel |
---|---|---|---|---|---|---|---|
Philips Brilliance 16 | 120 | x-y | 0.938 | 0.75 | 24 | 3 mm/1.5 mm | FBP / Standard (B) |
Philips Ingenuity CT | 120 | x-y-z | 0.999 (RS); 1.404 (FLL) | 0.75 (RS); 0.75 (FLL, 4, 8, 12, 16 mGy); 1.0 (FLL, 20 mGy)e | 40 | 2.5 mm/1.25 mm | iDose4 level 3 (out of 6) / Standard (B) |
Philips Brilliance iCT 256 | 120 | z | 1.014 (RS); 1.142 (FLL) | 0.75 | 40 | 2.5 mm/1.25 mm | iDose4 level 3 (out of 6) / Standard (B) |
Canon Aquilion RXL | 120 | OFF a (RS); x-y-z (FLL) | 1.000 (RS); 1.313 (FLL) | 0.75 | 32 | 3 mm/1.5 mm | AIDR 3D Standard / FC18 |
Canon Aquilion CXL | 120 | OFF a | 0.906 (RS); 1.297 (FLL) | 0.75 | 32 | 3 mm/1.5 mm | AIDR 3D Standard / FC18 |
Canon Aquilion ONE ViSION Edition | 120 | x-y-z | 0.950 (RS); 1.300 (FLL) | 0.75 | 40 | 3 mm/1.5 mm | AIDR 3D-enhanced Standard / FC08 |
GE BrightSpeed S | 120 | x-y-z | 0.938 (RS, 2, 6, 10, 15 mGy); 1.375 (RS, 4 mGy)c; 1.375 (FLL) | 0.8 (RS); 0.8 (FLL, 4, 8, 12, 16 mGy); 1.0 (FLL, 20 mGy)e | 20 | 2.5 mm/1.25 mm | ASIR 50% / Soft |
GE Discovery CT750 HD | 120 | x-y-z | 0.984 (RS); 1.375 (FLL) | 0.8 | 40 | 2.5 mm/1.25 mm | ASIR-V 70% / Standard (RS) ASIR-V 50% / Standard (FLL) |
GE Revolution CT | 120 | x-y-z | 0.984 (RS); 1.375 (FLL) | 0.8 | 40 | 2.5 mm/1.25 mm | ASIR-V 50% / Standard |
Siemens SOMATOM Emotion 16 | 130 | x-y-z | 1.000 (RS); 1.300 (FLL) | 1.0 (RS, 4, 6, 10, 15 mGy); 0.6 (RS, 2 mGy)e; 1.0 (FLL) | 19.2 | 3 mm/1.5 mm | FBP / B30s |
Siemens SOMATOM Definition Edge | 120 | x-y-z | 1.000 (RS); 1.300 (FLL) | 1.0 | 38.4 | 3 mm/1.5 mm | ADMIRE strength 3 (out of 5) / I30s |
Siemens SOMATOM Force | 120 | x-y-z | 1.000 (RS); 1.300 (FLL) | 1.0 | 57.6 | 3 mm/1.5 mm | ADMIRE strength 3 (out of 5) / Bf40s |
Radiation dose assessment
Image analysis
Low-contrast detectability
High-contrast detectability
Statistical analysis
Results
Low-contrast detectability
CT scanner | AUC (11 mGy, 8 mm lesions) | 95% confidence interval | AUC (9 mGy, 8 mm lesions) | 95% confidence interval | AUC (7 mGy, 8 mm lesions) | 95% confidence interval | AUC reduction (11 to 7 mGy) |
A1 | 0.956 | [0.947–0.965] | 0.945 | [0.930–0.959] | 0.929 | [0.914–0.944] | 2.8% |
A2 | 0.956 | [0.947–0.965] | 0.944 | [0.929–0.959] | 0.928 | [0.913–0.944] | 2.8% |
A3 | 0.972 | [0.966–0.978] | 0.960 | [0.945–0.974] | 0.941 | [0.927–0.956] | 3.1% |
B1 | 0.965 | [0.957–0.973] | 0.955 | [0.942–0.967] | 0.940 | [0.927–0.952] | 2.6% |
B2 | 0.964 | [0.956–0.971] | 0.954 | [0.939–0.968] | 0.939 | [0.924–0.953] | 2.6% |
B3 | 0.964 | [0.957–0.971] | 0.954 | [0.939–0.967] | 0.939 | [0.925–0.954] | 2.5% |
C1 | 0.977 | [0.971–0.982] | 0.967 | [0.955–0.978] | 0.952 | [0.940–0.964] | 2.4% |
C2 | 0.980 | [0.975–0.985] | 0.971 | [0.959–0.982] | 0.956 | [0.944–0.969] | 2.4% |
C3 | 0.979 | [0.973–0.983] | 0.972 | [0.965–0.978] | 0.963 | [0.952–0.972] | 1.7% |
D1 | 0.959 | [0.948–0.970] | 0.946 | [0.933–0.958] | 0.926 | [0.913–0.939] | 3.3% |
D2 | 0.943 | [0.932–0.954] | 0.926 | [0.906–0.946] | 0.903 | [0.884–0.922] | 4.3% |
D3 | 0.938 | [0.927–0.950] | 0.924 | [0.904–0.943] | 0.903 | [0.884–0.922] | 3.8% |
CT scanner | AUC (11 mGy, 5 mm lesions) | 95% confidence interval | AUC (9 mGy, 5 mm lesions) | 95% confidence interval | AUC (7 mGy, 5 mm lesions) | 95% confidence interval | AUC reduction (11 to 7 mGy) |
A1 | 0.872 | [0.853–0.891] | 0.854 | [0.827–0.880] | 0.830 | [0.801–0.858] | 4.8% |
A2 | 0.893 | [0.877–0.909] | 0.864 | [0.839–0.888] | 0.845 | [0.819–0.871] | 4.0% |
A3 | 0.879 | [0.861–0.897] | 0.879 | [0.855–0.902] | 0.860 | [0.837–0.884] | 3.6% |
B1 | 0.839 | [0.816–0.862] | 0.814 | [0.782–0.844] | 0.783 | [0.752–0.813] | 6.7% |
B2 | 0.870 | [0.852–0.889] | 0.852 | [0.822–0.880] | 0.829 | [0.799–0.859] | 4.7% |
B3 | 0.877 | [0.859–0.895] | 0.861 | [0.834–0.887] | 0.840 | [0.813–0.868] | 4.2% |
C1 | 0.902 | [0.886–0.918] | 0.879 | [0.853–0.905] | 0.851 | [0.825–0.876] | 5.7% |
C2 | 0.876 | [0.858–0.893] | 0.861 | [0.834–0.887] | 0.842 | [0.815–0.868] | 3.9% |
C3 | 0.864 | [0.844–0.884] | 0.844 | [0.819–0.869] | 0.819 | [0.787–0.849] | 5.6% |
D1 | 0.838 | [0.810–0.865] | 0.821 | [0.796–0.845] | 0.799 | [0.774–0.823] | 4.7% |
D2 | 0.816 | [0.793–0.840] | 0.791 | [0.751–0.830] | 0.761 | [0.723–0.799] | 6.8% |
D3 | 0.823 | [0.801–0.844] | 0.802 | [0.766–0.837] | 0.775 | [0.739–0.811] | 5.7% |