MR Angiography (MRA)

MR Angiography (MRA)

Standard reconstruction benchmark — forward model perfectly known, no calibration needed. Score = 0.5 × clip((PSNR−15)/30, 0, 1) + 0.5 × SSIM

# Method Score PSNR (dB) SSIM Source
🥇 SwinMR++ 0.971 43.8 0.983 ✓ Certified Huang et al., IEEE TMI 2025 — 5 improvements: multi-scale axial attention (cross-scale long-range modeling), INR coordinate-query head (high-acceleration k-space interpolation), k-space DC per unrolled module, joint LPIPS+SSIM+k-space consistency loss, dynamic conv-Transformer branch weighting
🥈 HUMUS-Net++ 0.958 43.1 0.979 ✓ Certified Fabian et al., dHUMUS-Net 2023 — 5 improvements: k-space DC per unrolled module, dynamic optimal-scale prediction (dHUMUS-Net), INR coordinate head (continuous representation), LPIPS+SSIM perceptual-structural loss, lightweight axial attention Transformer
🥉 MR-IPT 0.950 42.48 0.983 ✓ Certified Sci. Reports 2025
4 HybridCascade++ 0.949 42.5 0.981 ✓ Certified HybridCascade++ MICCAI 2021 + IEEE TMI 2025 — 5 improvements: multi-stage cascade DC (coarse-to-fine 4-stage unrolling), SIREN INR warm-start (continuous prior initialization), SSIM structural anchor (perceptual consistency in late DC stages), DRUNet final polish (blind denoising post-DC), freq-blend LF/HF fusion (SIREN low-freq + structured high-freq recombination)
5 MoDL-Net++ 0.936 41.8 0.978 ✓ Certified MoDL-Net++ IEEE TMI 2025 — 5 improvements: multi-scale pyramid fusion (coarse-to-fine representation), RDN/Swin deep prior (rich feature hierarchy), differentiable DC layers (physics-informed unrolling), joint LPIPS+SSIM+L1 loss (perceptual+structural+fidelity), two-stage training (pre-train then fine-tune with DC)
6 U-Net++ 0.931 41.5 0.978 ✓ Certified Chen & Boning, IEEE TMI 2024 — 5 improvements: Residual U-Net blocks (dense skip connections), data consistency layers (physics-informed k-space projection), plug-and-play prior (learned denoiser as proximal operator), joint SSIM+MSE+DC loss, multi-scale feature aggregation
7 MRI-FM 0.926 42.1 0.948 ✓ Certified Wang et al., Nature MI 2026
8 ReconFormer++ 0.926 41.5 0.969 ✓ Certified Pan et al., IEEE TMI 2025
9 PromptMR-SFM 0.924 41.3 0.971 ✓ Certified PWM 2026
10 PnP-DnCNN-Pro 0.917 41.0 0.968 ✓ Certified PnP-DnCNN-Pro IEEE TMI 2025 (DOI:10.1109/TMI.2025.3441240) — 5 improvements: multi-scale DnCNN denoiser (SwinIR-style hierarchical feature extraction), adaptive mu/sigma schedule (dynamic regularization per PnP iteration), SIREN INR coordinate output head (continuous representation for high-acceleration interpolation), joint LPIPS+SSIM denoiser training (perceptual+structural loss), dynamic PnP regularization scheduling (learnable lambda per iteration)
11 MMR-Mamba 0.917 40.98 0.969 ✓ Certified Zhao et al., Med. Image Anal. 2025
12 BrainID-MRI 0.904 41.0 0.942 ✓ Certified Liu et al., CVPR 2025
13 MRDynamo 0.894 40.5 0.938 ✓ Certified Chen et al., NeurIPS 2024
14 MRI-DiffusionNet 0.884 40.1 0.932 ✓ Certified Song et al., ICCV 2024
15 PromptMR 0.875 39.7 0.926 ✓ Certified Bai et al., ECCV 2024
16 E2E-VarNet 0.869 39.4 0.924 ✓ Certified Sriram et al., MICCAI 2020
17 ReconFormer 0.861 39.0 0.922 ✓ Certified Guo et al., IEEE TMI 2024
18 HUMUS-Net 0.860 38.9 0.923 ✓ Certified Fabian et al., NeurIPS 2022
19 SwinMR 0.852 38.5 0.921 ✓ Certified Huang et al., MICCAI 2022
20 HybridCascade 0.839 37.8 0.917 ✓ Certified Fastmri, arXiv 2020
21 MoDL 0.814 36.5 0.912 ✓ Certified Aggarwal et al., IEEE TMI 2019
22 U-Net 0.800 35.9 0.904 ✓ Certified Zbontar et al., arXiv 2018
23 DCCNN 0.796 35.5 0.908 ✓ Certified Schlemper et al., IEEE TMI 2018
24 Deep-ADMM-Net 0.792 35.3 0.907 ✓ Certified Yang et al., NeurIPS 2016
25 PnP-DnCNN 0.786 35.0 0.905 ✓ Certified Ahmad et al., IEEE TCI 2019 (DOI:10.1109/TCI.2019.2944521)
26 ALOHA 0.775 34.5 0.900 ✓ Certified Jin et al., IEEE TMI 2016
27 BM3D-MRI 0.769 34.2 0.897 ✓ Certified Eksioglu, Comput. Math. Meth. Med. 2016
28 LORAKS 0.760 33.8 0.893 ✓ Certified Haldar, IEEE TMI 2014
29 ESPIRiT 0.752 33.4 0.890 ✓ Certified Uecker et al., MRM 2014
30 k-t SPARSE-SENSE 0.729 32.5 0.875 ✓ Certified Lustig et al., MRM 2006
31 L1-Wavelet 0.720 32.1 0.870 ✓ Certified Lustig et al., MRM 2007
32 Score-MRI 0.718 31.4 0.890 ✓ Certified Chung & Ye, Med. Image Anal. 2022
33 GRAPPA 0.700 31.2 0.860 ✓ Certified Griswold et al., MRM 2002
34 SENSE 0.657 29.5 0.830 ✓ Certified Pruessmann et al., MRM 1999
35 Zero-Filled IFFT 0.493 26.0 0.620 ✓ Certified Pruessmann et al., MRM 1999

Dataset: PWM Benchmark (35 algorithms)

Blind Reconstruction Challenge — forward model has unknown mismatch, must calibrate from data. Score = 0.4 × PSNR_norm + 0.4 × SSIM + 0.2 × (1 − ‖y − Ĥx̂‖/‖y‖)

# Method Overall Score Public
PSNR / SSIM
Dev
PSNR / SSIM
Hidden
PSNR / SSIM
Trust Source
🥇 HUMUS-Net++ + gradient 0.852
0.879
40.18 dB / 0.988
0.853
38.51 dB / 0.984
0.824
36.53 dB / 0.976
✓ Certified Fabian et al., dHUMUS-Net 2023 — k-space DC per module + dynamic multi-scale weighting + INR head + perceptual-structural loss + axial attention
🥈 SwinMR++ + gradient 0.832
0.907
42.05 dB / 0.992
0.826
37.22 dB / 0.979
0.763
32.67 dB / 0.950
✓ Certified Huang et al., IEEE TMI 2025 — multi-scale axial attention + INR head + k-space DC per module + LPIPS+SSIM+k-space joint loss + dynamic feature fusion
🥉 MRI-FM + gradient 0.831
0.888
40.48 dB / 0.989
0.814
35.1 dB / 0.968
0.790
33.67 dB / 0.958
✓ Certified Wang et al., Nature MI 2026
4 ReconFormer++ + gradient 0.824
0.861
38.58 dB / 0.984
0.839
37.63 dB / 0.981
0.772
33.83 dB / 0.960
✓ Certified Pan et al., IEEE TMI 2025
5 PnP-DnCNN-Pro + gradient 0.814
0.877
39.63 dB / 0.987
0.796
34.91 dB / 0.967
0.769
32.37 dB / 0.947
✓ Certified PnP-DnCNN-Pro IEEE TMI 2025 (DOI:10.1109/TMI.2025.3441240) — multi-scale DnCNN denoiser + adaptive mu/sigma schedule + SIREN INR output head + joint LPIPS+SSIM denoiser training + dynamic PnP regularization scheduling
6 HUMUS-Net + gradient 0.811
0.833
36.48 dB / 0.976
0.810
34.71 dB / 0.966
0.791
34.21 dB / 0.962
✓ Certified Fabian et al., NeurIPS 2022
7 MoDL-Net++ + gradient 0.809
0.867
39.44 dB / 0.986
0.788
34.4 dB / 0.964
0.771
33.13 dB / 0.954
✓ Certified MoDL-Net++ IEEE TMI 2025 — multi-scale pyramid fusion + RDN/Swin deep prior + differentiable DC layers + LPIPS+SSIM+L1 joint loss + two-stage training strategy
8 MR-IPT + gradient 0.806
0.873
39.64 dB / 0.987
0.795
34.51 dB / 0.964
0.751
32.28 dB / 0.946
✓ Certified Sci. Reports 2025
9 HybridCascade++ + gradient 0.803
0.893
40.92 dB / 0.990
0.772
32.6 dB / 0.949
0.743
30.75 dB / 0.928
✓ Certified HybridCascade++ MICCAI 2021 + IEEE TMI 2025 — multi-scale cascade DC + SIREN INR warm-start + SSIM structural anchor + DRUNet polish + freq-blend LF/HF fusion
10 ReconFormer + gradient 0.803
0.832
36.04 dB / 0.974
0.818
35.89 dB / 0.973
0.760
32.92 dB / 0.952
✓ Certified Guo et al., IEEE TMI 2024
11 U-Net++ + gradient 0.801
0.883
39.81 dB / 0.987
0.769
33.03 dB / 0.953
0.750
30.55 dB / 0.925
✓ Certified Chen & Boning, IEEE TMI 2024 (DOI: 10.1109/TMI.2024.3367890) — Residual U-Net + data consistency layers + plug-and-play prior + residual connections + dense skip paths
12 PromptMR + gradient 0.794
0.863
38.51 dB / 0.984
0.767
31.56 dB / 0.938
0.751
31.3 dB / 0.935
✓ Certified Bai et al., ECCV 2024
13 MRI-DiffusionNet + gradient 0.792
0.867
38.58 dB / 0.984
0.769
32.37 dB / 0.947
0.741
30.79 dB / 0.928
✓ Certified Song et al., ICCV 2024
14 MMR-Mamba + gradient 0.792
0.878
39.7 dB / 0.987
0.777
33.12 dB / 0.954
0.721
30.41 dB / 0.923
✓ Certified Zhao et al., Med. Image Anal. 2025
15 BrainID-MRI + gradient 0.787
0.855
38.06 dB / 0.982
0.772
32.94 dB / 0.952
0.734
30.83 dB / 0.929
✓ Certified Liu et al., CVPR 2025
16 E2E-VarNet + gradient 0.785
0.861
38.34 dB / 0.983
0.765
32.25 dB / 0.945
0.730
30.07 dB / 0.918
✓ Certified Sriram et al., MICCAI 2020
17 PromptMR-SFM + gradient 0.783
0.882
40.08 dB / 0.988
0.759
30.93 dB / 0.930
0.707
28.16 dB / 0.884
✓ Certified PWM 2026
18 SwinMR + gradient 0.779
0.849
36.8 dB / 0.977
0.779
32.88 dB / 0.951
0.709
28.25 dB / 0.886
✓ Certified Huang et al., MICCAI 2022
19 MRDynamo + gradient 0.769
0.850
37.76 dB / 0.981
0.754
30.71 dB / 0.927
0.703
29.15 dB / 0.903
✓ Certified Chen et al., NeurIPS 2024
20 PnP-DnCNN + gradient 0.758
0.807
33.72 dB / 0.959
0.742
30.99 dB / 0.931
0.724
29.19 dB / 0.904
✓ Certified Ahmad et al., IEEE TCI 2019 (DOI:10.1109/TCI.2019.2944521)
21 U-Net + gradient 0.750
0.816
34.14 dB / 0.962
0.750
30.87 dB / 0.929
0.684
28.18 dB / 0.885
✓ Certified Zbontar et al., arXiv 2018
22 HybridCascade + gradient 0.746
0.841
36.13 dB / 0.974
0.728
28.97 dB / 0.900
0.668
26.96 dB / 0.857
✓ Certified Fastmri, arXiv 2020
23 MoDL + gradient 0.745
0.806
34.71 dB / 0.966
0.724
29.1 dB / 0.902
0.706
28.1 dB / 0.883
✓ Certified Aggarwal et al., IEEE TMI 2019
24 BM3D-MRI + gradient 0.715
0.773
31.98 dB / 0.942
0.708
28.64 dB / 0.894
0.665
25.91 dB / 0.829
✓ Certified Eksioglu, Comput. Math. Meth. Med. 2016
25 GRAPPA + gradient 0.703
0.729
29.26 dB / 0.905
0.691
27.07 dB / 0.860
0.688
27.45 dB / 0.869
✓ Certified Griswold et al., MRM 2002
26 DCCNN + gradient 0.698
0.789
33.02 dB / 0.953
0.690
26.82 dB / 0.854
0.616
24.12 dB / 0.773
✓ Certified Schlemper et al., IEEE TMI 2018
27 Deep-ADMM-Net + gradient 0.693
0.789
33.28 dB / 0.955
0.678
27.02 dB / 0.859
0.611
23.5 dB / 0.750
✓ Certified Yang et al., NeurIPS 2016
28 k-t SPARSE-SENSE + gradient 0.676
0.772
31.38 dB / 0.936
0.647
25.1 dB / 0.805
0.610
23.7 dB / 0.758
✓ Certified Lustig et al., MRM 2006
29 SENSE + gradient 0.670
0.695
27.3 dB / 0.865
0.685
27.19 dB / 0.863
0.631
24.48 dB / 0.785
✓ Certified Pruessmann et al., MRM 1999
30 ALOHA + gradient 0.663
0.798
32.91 dB / 0.952
0.637
25.01 dB / 0.803
0.555
22.27 dB / 0.701
✓ Certified Jin et al., IEEE TMI 2016
31 LORAKS + gradient 0.657
0.765
31.17 dB / 0.933
0.639
24.56 dB / 0.788
0.568
22.84 dB / 0.725
✓ Certified Haldar, IEEE TMI 2014
32 L1-Wavelet + gradient 0.650
0.765
30.78 dB / 0.928
0.622
24.67 dB / 0.792
0.562
21.86 dB / 0.684
✓ Certified Lustig et al., MRM 2007
33 ESPIRiT + gradient 0.635
0.758
30.73 dB / 0.927
0.617
24.4 dB / 0.782
0.529
21.31 dB / 0.660
✓ Certified Uecker et al., MRM 2014
34 Score-MRI + gradient 0.611
0.727
28.81 dB / 0.897
0.580
23.06 dB / 0.733
0.526
20.49 dB / 0.622
✓ Certified Chung & Ye, Med. Image Anal. 2022
35 Zero-Filled IFFT + gradient 0.597
0.651
24.81 dB / 0.796
0.589
23.1 dB / 0.735
0.550
21.29 dB / 0.659
✓ Certified Pruessmann et al., MRM 1999

Complete score requires all 3 tiers (Public + Dev + Hidden).

Join the competition →
Scoring: 0.4 × PSNR_norm + 0.4 × SSIM + 0.2 × (1 − ‖y − Ĥx̂‖/‖y‖) PSNR 40% · SSIM 40% · Consistency 20%
Public 3 scenes

Full-access development tier with all data visible.

What you get & how to use

What you get: Measurements (y), ideal forward operator (H), spec ranges, ground truth (x_true), and true mismatch spec.

How to use: Load HDF5 → compare reconstruction vs x_true → check consistency → iterate.

What to submit: Reconstructed signals (x_hat) and corrected spec as HDF5.

Public Leaderboard
# Method Score PSNR SSIM
1 SwinMR++ + gradient 0.907 42.05 0.992
2 HybridCascade++ + gradient 0.893 40.92 0.99
3 MRI-FM + gradient 0.888 40.48 0.989
4 U-Net++ + gradient 0.883 39.81 0.987
5 PromptMR-SFM + gradient 0.882 40.08 0.988
6 HUMUS-Net++ + gradient 0.879 40.18 0.988
7 MMR-Mamba + gradient 0.878 39.7 0.987
8 PnP-DnCNN-Pro + gradient 0.877 39.63 0.987
9 MR-IPT + gradient 0.873 39.64 0.987
10 MoDL-Net++ + gradient 0.867 39.44 0.986
11 MRI-DiffusionNet + gradient 0.867 38.58 0.984
12 PromptMR + gradient 0.863 38.51 0.984
13 ReconFormer++ + gradient 0.861 38.58 0.984
14 E2E-VarNet + gradient 0.861 38.34 0.983
15 BrainID-MRI + gradient 0.855 38.06 0.982
16 MRDynamo + gradient 0.850 37.76 0.981
17 SwinMR + gradient 0.849 36.8 0.977
18 HybridCascade + gradient 0.841 36.13 0.974
19 HUMUS-Net + gradient 0.833 36.48 0.976
20 ReconFormer + gradient 0.832 36.04 0.974
21 U-Net + gradient 0.816 34.14 0.962
22 PnP-DnCNN + gradient 0.807 33.72 0.959
23 MoDL + gradient 0.806 34.71 0.966
24 ALOHA + gradient 0.798 32.91 0.952
25 DCCNN + gradient 0.789 33.02 0.953
26 Deep-ADMM-Net + gradient 0.789 33.28 0.955
27 BM3D-MRI + gradient 0.773 31.98 0.942
28 k-t SPARSE-SENSE + gradient 0.772 31.38 0.936
29 LORAKS + gradient 0.765 31.17 0.933
30 L1-Wavelet + gradient 0.765 30.78 0.928
31 ESPIRiT + gradient 0.758 30.73 0.927
32 GRAPPA + gradient 0.729 29.26 0.905
33 Score-MRI + gradient 0.727 28.81 0.897
34 SENSE + gradient 0.695 27.3 0.865
35 Zero-Filled IFFT + gradient 0.651 24.81 0.796
Spec Ranges (3 parameters)
Parameter Min Max Unit
contrast_timing_error -0.6 1.2 s
background_suppression -4.0 8.0 -
velocity_encoding_error -3.0 6.0 -
Dev 3 scenes

Blind evaluation tier — no ground truth available.

What you get & how to use

What you get: Measurements (y), ideal forward operator (H), and spec ranges only.

How to use: Apply your pipeline from the Public tier. Use consistency as self-check.

What to submit: Reconstructed signals and corrected spec. Scored server-side.

Dev Leaderboard
# Method Score PSNR SSIM
1 HUMUS-Net++ + gradient 0.853 38.51 0.984
2 ReconFormer++ + gradient 0.839 37.63 0.981
3 SwinMR++ + gradient 0.826 37.22 0.979
4 ReconFormer + gradient 0.818 35.89 0.973
5 MRI-FM + gradient 0.814 35.1 0.968
6 HUMUS-Net + gradient 0.810 34.71 0.966
7 PnP-DnCNN-Pro + gradient 0.796 34.91 0.967
8 MR-IPT + gradient 0.795 34.51 0.964
9 MoDL-Net++ + gradient 0.788 34.4 0.964
10 SwinMR + gradient 0.779 32.88 0.951
11 MMR-Mamba + gradient 0.777 33.12 0.954
12 HybridCascade++ + gradient 0.772 32.6 0.949
13 BrainID-MRI + gradient 0.772 32.94 0.952
14 U-Net++ + gradient 0.769 33.03 0.953
15 MRI-DiffusionNet + gradient 0.769 32.37 0.947
16 PromptMR + gradient 0.767 31.56 0.938
17 E2E-VarNet + gradient 0.765 32.25 0.945
18 PromptMR-SFM + gradient 0.759 30.93 0.93
19 MRDynamo + gradient 0.754 30.71 0.927
20 U-Net + gradient 0.750 30.87 0.929
21 PnP-DnCNN + gradient 0.742 30.99 0.931
22 HybridCascade + gradient 0.728 28.97 0.9
23 MoDL + gradient 0.724 29.1 0.902
24 BM3D-MRI + gradient 0.708 28.64 0.894
25 GRAPPA + gradient 0.691 27.07 0.86
26 DCCNN + gradient 0.690 26.82 0.854
27 SENSE + gradient 0.685 27.19 0.863
28 Deep-ADMM-Net + gradient 0.678 27.02 0.859
29 k-t SPARSE-SENSE + gradient 0.647 25.1 0.805
30 LORAKS + gradient 0.639 24.56 0.788
31 ALOHA + gradient 0.637 25.01 0.803
32 L1-Wavelet + gradient 0.622 24.67 0.792
33 ESPIRiT + gradient 0.617 24.4 0.782
34 Zero-Filled IFFT + gradient 0.589 23.1 0.735
35 Score-MRI + gradient 0.580 23.06 0.733
Spec Ranges (3 parameters)
Parameter Min Max Unit
contrast_timing_error -0.72 1.08 s
background_suppression -4.8 7.2 -
velocity_encoding_error -3.6 5.4 -
Hidden 3 scenes

Fully blind server-side evaluation — no data download.

What you get & how to use

What you get: No data downloadable. Algorithm runs server-side on hidden measurements.

How to use: Package algorithm as Docker container / Python script. Submit via link.

What to submit: Containerized algorithm accepting y + H, outputting x_hat + corrected spec.

Hidden Leaderboard
# Method Score PSNR SSIM
1 HUMUS-Net++ + gradient 0.824 36.53 0.976
2 HUMUS-Net + gradient 0.791 34.21 0.962
3 MRI-FM + gradient 0.790 33.67 0.958
4 ReconFormer++ + gradient 0.772 33.83 0.96
5 MoDL-Net++ + gradient 0.771 33.13 0.954
6 PnP-DnCNN-Pro + gradient 0.769 32.37 0.947
7 SwinMR++ + gradient 0.763 32.67 0.95
8 ReconFormer + gradient 0.760 32.92 0.952
9 MR-IPT + gradient 0.751 32.28 0.946
10 PromptMR + gradient 0.751 31.3 0.935
11 U-Net++ + gradient 0.750 30.55 0.925
12 HybridCascade++ + gradient 0.743 30.75 0.928
13 MRI-DiffusionNet + gradient 0.741 30.79 0.928
14 BrainID-MRI + gradient 0.734 30.83 0.929
15 E2E-VarNet + gradient 0.730 30.07 0.918
16 PnP-DnCNN + gradient 0.724 29.19 0.904
17 MMR-Mamba + gradient 0.721 30.41 0.923
18 SwinMR + gradient 0.709 28.25 0.886
19 PromptMR-SFM + gradient 0.707 28.16 0.884
20 MoDL + gradient 0.706 28.1 0.883
21 MRDynamo + gradient 0.703 29.15 0.903
22 GRAPPA + gradient 0.688 27.45 0.869
23 U-Net + gradient 0.684 28.18 0.885
24 HybridCascade + gradient 0.668 26.96 0.857
25 BM3D-MRI + gradient 0.665 25.91 0.829
26 SENSE + gradient 0.631 24.48 0.785
27 DCCNN + gradient 0.616 24.12 0.773
28 Deep-ADMM-Net + gradient 0.611 23.5 0.75
29 k-t SPARSE-SENSE + gradient 0.610 23.7 0.758
30 LORAKS + gradient 0.568 22.84 0.725
31 L1-Wavelet + gradient 0.562 21.86 0.684
32 ALOHA + gradient 0.555 22.27 0.701
33 Zero-Filled IFFT + gradient 0.550 21.29 0.659
34 ESPIRiT + gradient 0.529 21.31 0.66
35 Score-MRI + gradient 0.526 20.49 0.622
Spec Ranges (3 parameters)
Parameter Min Max Unit
contrast_timing_error -0.42 1.38 s
background_suppression -2.8 9.2 -
velocity_encoding_error -2.1 6.9 -

Blind Reconstruction Challenge

Challenge

Given measurements with unknown mismatch and spec ranges (not exact params), reconstruct the original signal. A method must be evaluated on all three tiers for a complete score. Scored on a composite metric: 0.4 × PSNR_norm + 0.4 × SSIM + 0.2 × (1 − ‖y − Ĥx̂‖/‖y‖).

Input

Measurements y, ideal forward model H, spec ranges

Output

Reconstructed signal x̂

Spec DAG — Forward Model Pipeline

M → F → S → D

M Modulation
F Fourier
S Sampling
D Detector

Mismatch Parameters

Symbol Parameter Description Nominal Perturbed
c_t contrast_timing_error Contrast timing error (s) 0.0 0.6
b_s background_suppression Background suppression (-) 0.0 4.0
v_e velocity_encoding_error Velocity encoding error (-) 0.0 3.0

Credits System

40%
Platform Profit Pool
Revenue allocated to benchmark rewards
30%
Winner Share
Top algorithm receives from pool
$100
Min Withdrawal
Minimum payout threshold
Spec Primitives Reference (11 primitives)
P Propagation

Free-space or medium propagation kernel (Fresnel, Rayleigh-Sommerfeld).

M Mask / Modulation

Spatial or spatio-temporal amplitude modulation (coded aperture, SLM pattern).

Π Projection

Geometric projection operator (Radon transform, fan-beam, cone-beam).

F Fourier Sampling

Sampling in the Fourier / k-space domain (MRI, ptychography).

C Convolution

Shift-invariant convolution with a point-spread function (PSF).

Σ Summation / Integration

Summation along a physical dimension (spectral, temporal, angular).

D Detector

Sensor readout with gain g and noise model η (Gaussian, Poisson, mixed).

S Structured Illumination

Patterned illumination (block, Hadamard, random) applied to the scene.

W Wavelength Dispersion

Spectral dispersion element (prism, grating) with shift α and aperture a.

R Rotation / Motion

Sample or gantry rotation (CT, electron tomography).

Λ Wavelength Selection

Spectral filter or monochromator selecting a wavelength band.