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©The Author(s) 2023.
World J Radiol. Dec 28, 2023; 15(12): 338-349
Published online Dec 28, 2023. doi: 10.4329/wjr.v15.i12.338
Published online Dec 28, 2023. doi: 10.4329/wjr.v15.i12.338
Table 1 Details of imaging parameters
Parameters | FOCUS-DLR+/– | FOCUS-conv |
Repetition time, ms | 3000–10000 | 3500–15000 |
Echo time, ms | 60 | 60 |
Flip angle, degree | 90 | 90 |
FOV, mm2 | 220 × 110 | 220 × 110 |
Matrix | 120 × 64 | 130 × 40 |
FOV reduction | Anterior-posterior | Anterior-posterior |
Slice thickness, mm | 3 | 4 |
Slice gap, mm | 3 | 5 |
Number of slices | 20–30 | 15–20 |
Number of excitations | 4 | 8 |
b-values, s/mm2 | 0 and 600 | 0 and 600 |
Band width, Hz/pixel | 1950 | 1300 |
Respiratory compensation | Respiratory-triggered with navigator echo | Respiratory-triggered with or without navigator echo |
Deep learning reconstruction factor | Moderate | N/A |
Scan time, min | 2–5 | 3–10 |
Table 2 Image-quality scores in the qualitative assessment
Qualitative assessment | 1 | 2 | 3 | 4 |
Sharpness of the pancreas contour | Entire pancreas contour is unclear | < 50% of the pancreas contour is clear | ≥ 50% of the pancreas contour is clear | Entire pancreas contour is clear |
Image noise | Severe noise; no visualization of any organs | Moderate noise; compromised diagnostic capability of FOCUS is more than ≥ 50% of the image | Mild noise; compromised the diagnostic capability of FOCUS is < 50% of the image | No or slight noise on the image |
Distortion of the pancreas | Severe distortion; no visualization of the whole pancreas | Moderate distortion; no visualization is ≥ 50% of the pancreas | Mild distortion; no visualization is < 50% of the pancreas | No distortion of the pancreas |
Visualization of pancreas cystic lesion | No visualization of pancreas cystic lesion | Pancreas cystic lesion is visible, but its SI is low | Pancreas cystic lesion is visible with high SI, but its contour is unclear | Pancreas cystic lesion is clearly visible with high SI and clear contour |
Visualization of MPD on ADC map | No visualization of MPD | Visible MPD is < 50% of the pancreas | Visible MPD is ≥ 50% of the pancreas | Whole MPD is visible |
Table 3 The results of the two radiologists' qualitative assessments
Qualitative assessment | Reader | Mean image-quality score | P value | |||||
Friedman test | Bonferroni post-hoc test | |||||||
FOCUS-DLR+ | FOCUS-DLR- | FOCUS-conv | FOCUS-DLR+ vs FOCUS-DLR- | FOCUS-DLR+ vs FOCUS-conv | FOCUS-DLR- vs FOCUS-conv | |||
Sharpness of pancreas contour | R1 | 3.32 | 3 | 2.24 | < 0.0011 | 0.31 | < 0.0011 | 0.0011 |
R2 | 3.32 | 3.03 | 2.05 | < 0.0011 | 0.49 | < 0.0011 | < 0.0011 | |
Image noise | R1 | 3.65 | 2.7 | 2.86 | < 0.00 11 | < 0.0011 | < 0.0011 | 1 |
R2 | 3.59 | 2.54 | 2.7 | < 0.0011 | < 0.0011 | < 0.0011 | 0.97 | |
Distortion of pancreas | R1 | 3.16 | 3.11 | 3.05 | 0.05 | N/A | N/A | N/A |
R2 | 3.11 | 3.18 | 3.05 | 0.73 | N/A | N/A | N/A | |
Visualization of pancreas cystic lesion | R1 | 3.7 | 3.49 | 2.89 | < 0.0011 | 0.67 | 0.0161 | 0.35 |
R2 | 3.62 | 3.32 | 2.7 | < 0.0011 | 0.24 | 0.0011 | 0.17 | |
Visualization of MPD on ADC map | R1 | 2.97 | 2.54 | 2.19 | < 0.0011 | 0.17 | 0.0031 | 0.49 |
R2 | 2.73 | 2.24 | 1.99 | < 0.0011 | 0.11 | 0.0011 | 0.35 |
Table 4 Inter-reader agreement between the two radiologists
Qualitative assessment | Imaging | κ value (95%CI) | P value |
Sharpness of pancreas contour | FOCUS-DLR+ | 0.73 (0.52–0.95) | < 0.0011 |
FOCUS-DLR- | 0.69 (0.45–0.93) | < 0.0011 | |
FOCUS-conv | 0.66 (0.43–0.89) | < 0.0011 | |
Image noise | FOCUS-DLR+ | 0.69 (0.46–0.92) | < 0.0011 |
FOCUS-DLR- | 0.70 (0.50–0.90) | < 0.0011 | |
FOCUS-conv | 0.64 (0.42–0.87) | < 0.0011 | |
Distortion of pancreas | FOCUS-DLR+ | 0.61 (0.40–0.82) | < 0.0011 |
FOCUS-DLR- | 0.71 (0.53–0.89) | < 0.0011 | |
FOCUS-conv | 0.61 (0.41–0.82) | < 0.0011 | |
Visualization of pancreas cystic lesion | FOCUS-DLR+ | 0.80 (0.56–1.03) | < 0.0011 |
FOCUS-DLR- | 0.76 (0.60–0.93) | < 0.0011 | |
FOCUS-conv | 0.71 (0.51–0.91) | < 0.0011 | |
Visualization of MPD on ADC map | FOCUS-DLR+ | 0.67 (0.51–0.83) | < 0.0011 |
FOCUS-DLR- | 0.75 (0.60–0.90) | < 0.0011 | |
FOCUS-conv | 0.74 (0.54–0.94) | < 0.0011 |
Table 5 The results of quantitative assessments
Quantitative assessments | mean ± SD | P values | |||||
Friedman test | Bonferroni post-hoc test | ||||||
FOCUS-DLR+ | FOCUS-DLR- | FOCUS-conv | FOCUS-DLR+ vs FOCUS-DLR- | FOCUS-DLR+ vs FOCUS-conv | FOCUS-DLR- vs FOCUS-conv | ||
CRpancreas-fat on FOCUS with b value of 600 s/mm2 | 0.68 ± 0.08 | 0.49 ± 0.10 | 0.27 ± 0.11 | < 0.0011 | < 0.0011 | < 0.0011 | < 0.0011 |
CRpancreas-fat on FOCUS with b value of 0 s/mm2 | 0.72 ± 0.08 | 0.65 ± 0.08 | 0.40 ± 0.11 | < 0.0011 | < 0.0011 | < 0.0011 | < 0.0011 |
CRlesion-pancreas on FOCUS with b value of 600 s/mm2 | 0.51 ± 0.26 | 0.62 ± 0.21 | 0.01 ± 0.26 | < 0.0011 | < 0.0011 | < 0.0011 | < 0.0011 |
CRlesion-pancreas on FOCUS with b value of 0 s/mm2 | 0.53 ± 0.21 | 0.62 ± 0.21 | 0.17 ± 0.19 | < 0.0011 | < 0.0011 | < 0.0011 | < 0.0011 |
ADCpancreas+ (× 10-3 mm2/s) | 1.44 ± 0.24 | 1.39 ± 0.22 | 1.84 ± 0.45 | < 0.0011 | < 0.0011 | < 0.0011 | < 0.0011 |
ADClesion (× 10-3 mm2/s) | 3.00 ± 0.66 | 2.86 ± 0.61 | 3.32 ± 0.70 | < 0.0011 | < 0.0011 | < 0.0011 | < 0.0011 |
- Citation: Takayama Y, Sato K, Tanaka S, Murayama R, Goto N, Yoshimitsu K. Deep learning-based magnetic resonance imaging reconstruction for improving the image quality of reduced-field-of-view diffusion-weighted imaging of the pancreas. World J Radiol 2023; 15(12): 338-349
- URL: https://www.wjgnet.com/1949-8470/full/v15/i12/338.htm
- DOI: https://dx.doi.org/10.4329/wjr.v15.i12.338