Table 6.
Result of qualitative image quality assessment for the abdomen and aorta.
| Abdomen | |||||
|---|---|---|---|---|---|
| Author (year) | % iodine reduction | VMIs (keV) | CNR (SECT vs. DECT) |
SNR (SECT vs. DECT) |
Subjective image quality assessment (SECT vs. DECT) |
| Clark et al. (2015) [34] | 37 | 52 | Liver, 1.1 (0.8) vs. 0.70 (0.8); pancreas, 2.6 (1.9) vs. 2.3 (1.7); abd. aorta, 14.5 (5.8) vs. 13.4 (5.6) | N/A | 5-point scale, acceptable or good overall image quality, higher or similar noise |
| Ma et al. 2016) [40] | 25 | 60 | Portal v., intrahepatic, 3.0 (2.1) vs. 4.2 (1.1) ‡; extrahepatic, 5.9 (1.6) vs. 5.9 (1.4) | N/A | 5-point scale, good or excellent overall image quality |
| Lv et al. (2017) [39] | 33 | 40 | Liver, HAP, 1.0 (0.8) vs. 1.3 (1.2); PVP, 2.7 (1.9) vs. 4.5 (2.3) †; Portal v., PVP, 5.23 (3.4) vs. 10.2 (2.9) †; Abd. aorta, AP, 12.7 (4.4) vs. 21.2 (6.5) † | N/A | 5-point scale, moderate overall image quality and noise |
| Li et al. (2018) [38] | 41 | 52 | Lesion-to-liver, HAP, 15.77 (5.93) vs. 19.51 (6.29) ‡; PVP, 8.19 (3.04) vs. 9.96 (2.18) ‡ | N/A | 4-point scale, moderate noise and above average diagnostic acceptability; better lesion conspicuity for 50 keV VMIs † |
| Nagayama et al. (2018) [41] | 50 | 40 | Liver, PVP, 6 vs. 10 †; EP, 3 vs. 5 †; Tumor-to-liver, HAP, 3.4 (1.2) vs. 8.3 (3.1) †; PVP, −1.9 (1.1) vs. −2.4 (2.0); EP, −2.1 (0.9) vs. −2.9 (1.7); abd. aorta, HAP, 22 vs. 55 † | N/A | 5-point scale, average or above average vs. above average or excellent overall image quality †; moderate or minor noise |
| Kim et al. (2019) [36] | 30 | 40 | Hyper-enhancing lesion-to-liver, 1.11 (0.61–1.47) vs. 3.77 (3.11–5.02) †; hypo-enhancing lesion-to-liver 2.98 (1.12) vs. 2.72 (1.41) | Liver, HAP, 3.91 (0.74) vs. 3.08 (0.80) †; PVP, 6.66 (1.05) vs. 6.40 (1.21); Portal v., PVP, 10.99 (10.02–11.50) vs. 12.87 (2.04) †; pancreas, HAP, 7.20 (1.60) vs. 7.50 (1.80); PVP, 5.58 (0.90) vs. 5.88 (0.96); Abd. aorta, HAP, 20.24 (3.99) vs. 23.54 (4.74) †; | 6-point scale, 50 keV VMIs superior to SECT |
| Han et al. (2019) [35] | 50 | 50 | Portal v., intrahepatic, 3.15 (1.29) vs. 3.16 (1.19); extrahepatic 6.83 (1.66) vs. 5.75 (2.28) | N/A | 5-point scale, good or excellent |
| Shuman et al. (2019) [21] | 50 | 50 | Kidneys, NP, 21 (9) vs. 26 (8) ‡; renal art. and v.; NP, 13 (6) and 13 (8) vs. 13 (4) and 13 (5); calyces and pelvis, DP, 166 (112) vs. 255 (201) ‡; ureters 172 (96) vs. 195 (131); bladder, 113 (62) vs. 182 (141) ‡ | N/A | 4-point scale, moderate or good overall image quality and minor noise |
| Lennartz et al. (2020) [37] | 50 | 40 | Lymph nodes/Aorta, 15.2 (4.9) vs. 23.7 (8.9) ‡; Lymph nodes/Portal v., 17.5 (4.9) vs. 25.4 (9.0) ‡ | Liver, 10.0 (3.0) vs. 9.1 (3.9); pancreas, 8.0 (2.3) vs. 8.3 (3.5); Portal v., 14.8 (4.2) vs. 16.9 (6.4); kidneys, 15.8 (4.8) vs. 17.7 (6.7); abd. aorta, 13.8 (4.0) vs. 16.1 (6.6) |
4-point scale, excellent vs. proper overall image quality ‡; minimal vs. little noise ‡ |
| Aorta | |||||
| Carrascosa et al. (2014) [43] |
50 or 60 or 70 | 40 | N/A | Thoraco-abd. aorta, 15.7 (8.7) vs. 15.3 (5.9) or 16.2 (8.3) or 14.1 (5.6) | 10-point scale, very good quality and minimal noise; good quality with some noise for 70% reduction |
| Liu et al. (2016) [45] | 23 | 65 | Abd. aorta, 12.59 (2.64) vs. 16.14 (4.31) ‡ | N/A | 5-point scale |
| Agrawal et al. (2016) [42] | 28 | 40 | 15.4 (6) vs. 19.3 (7.3) ‡ | 18 (6.6) vs. 21.1 (7.6) ‡ | 5-point scale, good overall image quality; minimal vs. moderate noise |
| Hou et al. (2017) [44] | 40 or 59 | 60 or 55 | Asc. aorta, 14.6 (2.7) vs. 24.3 (8.2) † or 16.8 (3.5); desc. aorta, 13.9 (2.9) vs. 22.8 (7.5) † or 17.0 (4.0); celiac art, 14.2 (3.0) vs. 22.1 (6.9) † or 16.0 (2.9); renal art, 14.5 (3.3) vs. 21.9 (6.5) † or 16.5 (3.3); iliac art, 14.3 (3.1) vs. 23.5 (7.0) † or 16.9 (3.5) | N/A | 5-point scale, good overall image quality with low noise |
| Patino et al. (2019) [46] | 52 | 40 | Abd. Aorta, 18 (7) vs. 19 (5) | N/A | 5-point scale, good or excellent overall image quality |
| Sugawara et al. (2019) [47] | 50 | 52 | Abd. aorta, 13.5 (2.6) vs. 16.8 ± 4.5 ‡; celiac art, 13.2 (2.7) vs. 16.3 ± 4.4 ‡; sup. mesenteric art, 13.3 (2.8) vs. 15.6 ± 4.0 | N/A | 4-point scale, completely visible |
† p > 0.01; ‡ p < 0.05. VMIs, virtual monoenergetic images; CNR, contrast to noise ratio; SNR, signal to noise ratio; DECT, dual energy CT; SECT, single energy CT; HAP, hepatic arterial phase; PVP, portal venous phase; EP, equilibrium phase; NP, nephrographic phase; DP, delayed phase; N/A, not available.