TABLE 2.
Description of the phantom image cases and results from the assessment of metal artifacts.
| kVp | IQ | Kernel | iMAR | VMI (keV) | Slice Thickness (mm) | DiffHU (metal‐normal) | SDARTIFACT (HU) | BloomVol (cm3) | AmplitudeLowFreq | CV (%) | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | VGSUM | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Case 1 | 120 | 80 | Bv40f | Ex | 110 | 0.4 | −86 | 50 | 61.6 | 42723.6 | 5.4 | 5 | 1 | 1 | 2 | 3 | 3 | 15 |
| Case 2 | 120 | 80 | Bv40f | Hi | 110 | 0.4 | −66 | 67 | 61.2 | 43578.6 | 2.3 | 4 | 1 | 3 | 2 | 3 | 4 | 17 |
| Case 3 | 120 | 80 | Bv40f | Th | 110 | 0.4 | −131 | 141 | 61.7 | 44911.3 | 3.9 | 2 | 1 | 2 | 0 | 0 | 2 | 7 |
| Case 4 | 120 | 80 | Bv40f | None | 110 | 0.4 | −213 | 128 | 62.6 | 40267.9 | 13.8 | 1 | 4 | 0 | 0 | 3 | 4 | 12 |
| Case 5 | 120 | 80 | Bv40f | Pa | 110 | 0.4 | −134 | 107 | 61.6 | 38909.2 | 6.6 | 3 | 2 | 3 | 2 | 3 | 4 | 17 |
| Case 6 | 120 | 100 | Qr40f | Pa | 110 | 0.4 | −119 | 151 | 59.9 | 44501.0 | 11.0 | 3 | 2 | 3 | 2 | 4 | 3 | 17 |
| Case 7 | 140 | 55 | Qr40f | Pa | 110 | 0.4 | −99 | 99 | 59.1 | 52724.3 | 9.5 | 4 | 5 | 3 | 1 | 4 | 1 | 18 |
| Case 8 | 140 | 60 | Qr40f | Pa | 110 | 0.4 | −51 | 140 | 58.5 | 38961.9 | 3.4 | 5 | 4 | 3 | 1 | 4 | 5 | 22 |
| Case 9 | 120 | 55 | Qr40f | Pa | 110 | 0.4 | −137 | 168 | 61.3 | 52770.9 | 4.0 | 3 | 2 | 3 | 1 | 4 | 5 | 18 |
| Case 10 | 120 | 60 | Qr40f | Pa | 110 | 0.4 | −108 | 150 | 60.0 | 39782.8 | 5.3 | 3 | 2 | 3 | 2 | 4 | 4 | 18 |
| Case 11 | 120 | 80 | Bl56f | Pa | 110 | 0.4 | −45 | 145 | 42.3 | 52021.7 | 3.5 | 4 | 3 | 2 | 1 | 2 | 1 | 13 |
| Case 12 | 120 | 80 | Bv36f | Pa | 110 | 0.4 | −115 | 133 | 62.7 | 46673.0 | 13.0 | 4 | 3 | 3 | 1 | 3 | 4 | 18 |
| Case 13 | 120 | 80 | Bv40f | Pa | 110 | 0.4 | −72 | 120 | 61.8 | 41604.8 | 4.3 | 2 | 3 | 3 | 2 | 3 | 4 | 17 |
| Case 14 | 120 | 80 | Bv44f | Pa | 110 | 0.4 | −103 | 108 | 61.2 | 42936.0 | 1.6 | 4 | 2 | 3 | 1 | 3 | 4 | 17 |
| Case 15 | 120 | 80 | Bv56f | Pa | 110 | 0.4 | −99 | 138 | 56.0 | 44470.7 | 5.7 | 3 | 1 | 1 | 0 | 2 | 2 | 9 |
| Case 16 | 120 | 80 | Qr36f | Pa | 110 | 0.4 | −133 | 123 | 60.6 | 42913.5 | 2.2 | 4 | 4 | 3 | 1 | 3 | 3 | 18 |
| Case 17 | 120 | 80 | Qr40f | Pa | 110 | 0.4 | −115 | 118 | 60.2 | 43677.7 | 1.8 | 2 | 4 | 4 | 3 | 4 | 3 | 20 |
| Case 18 | 120 | 80 | Qr44f | Pa | 110 | 0.4 | −132 | 126 | 58.5 | 43448.0 | 3.8 | 3 | 4 | 3 | 1 | 4 | 3 | 18 |
| Case 19 | 120 | 80 | Qr40f | Pa | 40 | 0.4 | −109 | 207 | 89.8 | 37437.5 | 5.4 | 0 | 2 | 1 | 0 | 1 | 0 | 4 |
| Case 20 | 120 | 80 | Qr40f | Pa | 62 | 0.4 | −86 | 134 | 84.6 | 39828.3 | 5.7 | 0 | 4 | 1 | 0 | 3 | 3 | 11 |
| Case 21 | 120 | 80 | Qr40f | Pa | 190 | 0.4 | −108 | 158 | 52.6 | 47422.1 | 1.1 | 2 | 2 | 3 | 1 | 2 | 3 | 13 |
| Case 22 | 120 | 80 | Bv40f | None | 70 | 1 | −150 | 165 | 80.0 | 38917.6 | 0.8 | 2 | 4 | 3 | 2 | 5 | 5 | 21 |
| Case 23 | 120 | 80 | Qr40f | None | 70 | 1 | −143 | 170 | NA | 40270.2 | 1.3 | 3 | 5 | 1 | 2 | 3 | 3 | 17 |
| Case 24 | 120 | 80 | Qr40f | None | T3D | 0.4 | 46 | 211 | 83.3 | 43657.8 | 3.0 | 0 | 1 | 1 | 1 | 4 | 3 | 10 |
| Case 25 | 140 | 80 | Qr40f | Pa | 40 | 0.4 | −273 | 275 | 92.7 | 45531.2 | 7.0 | 0 | 3 | 0 | 0 | 1 | 1 | 5 |
| Case 26 | 140 | 80 | Qr40f | Pa | 67 | 0.4 | −141 | 143 | 81.5 | 46290.3 | 7.0 | 1 | 3 | 0 | 0 | 1 | 1 | 6 |
| Case 27 | 140 | 80 | Qr40f | Pa | 110 | 0.4 | −121 | 96 | 59.6 | 56096.3 | 5.5 | 3 | 4 | 3 | 1 | 3 | 3 | 17 |
| Case 28 | 140 | 80 | Qr40f | Pa | T3D | 0.4 | −142 | 129 | 75.0 | 55114.1 | 3.4 | 3 | 6 | 3 | 3 | 5 | 3 | 23 |
| Case 29 | 90 | 80 | Qr40f | Pa | 110 | 0.4 | −14 | 147 | 65.2 | 45112.8 | 2.2 | 1 | 0 | 3 | 0 | 2 | 1 | 7 |
| Case 30 | 90 | 80 | Qr40f | Pa | T3D | 0.4 | −170 | 199 | 85.0 | 45160.2 | 7.1 | 0 | 4 | 1 | 0 | 2 | 1 | 8 |
| Case 31 | 120 | 80 | Bv40f | Pa | T3D | 0.4 | −140 | 141 | 79.0 | 49692.4 | 3.0 | 3 | 5 | 3 | 1 | 4 | 3 | 19 |
| Case 32 | 120 | 80 | Qr40f | Pa | 110 | 0.4 | −39 | 137 | 60.3 | 48914.2 | 1.5 | 3 | 4 | 3 | 1 | 4 | 4 | 19 |
| Case 33 | 120 | 80 | Qr40f | Pa | 110 | 1 | −123 | 108 | 60.3 | 50246.3 | 2.4 | 3 | 5 | 3 | 3 | 3 | 3 | 20 |
| Case 34 | 120 | 80 | Qr40f | Pa | 110 | 3 | −136 | 108 | 61.8 | 48888.0 | 3.7 | 5 | 4 | 6 | 2 | 5 | 3 | 25 |
| Case 35 | 140 | 80 | Qr40f | Pa | 110 | 1 | −97 | 89 | 59.4 | 51022.6 | 2.7 | 4 | 5 | 3 | 3 | 4 | 3 | 22 |
| Case 36 | 140 | 80 | Qr40f | Pa | 110 | 3 | −140 | 81 | 60.8 | 51012.5 | 5.4 | 5 | 5 | 3 | 3 | 5 | 4 | 25 |
Note: The acquisition parameters, kVp and IQ (image quality) level, and the reconstruction parameters, kernel, iMAR (iterative metal artifact reduction), and virtual mono‐energetic image (VMI), varied across the image cases. The results from manual ROI analyses included the difference in Hounsfield Units (HU) between areas with metal artifacts and normal tissue (DiffHU—Metal minus normal), and the standard deviation in areas affected by metal artifacts (SDARTIFACT). The volume from the blooming assessment (BloomVol) and the results from the streak artifact assessment, the amplitude of low frequencies in bin 1−2 (AmplitudeLowFreq) and the associated coefficient of variation (CV). The occurrence of grade 3, 4, and 5 responses for visual grading of metal artifact (Q1) and diagnostic interpretability (Q2–Q6), and their respective sums (VGSUM).