Equivariance2Inverse: A Practical Self-Supervised CT Reconstruction Method Benchmarked on Real, Limited-Angle, and Blurred Data
Pith reviewed 2026-05-18 03:21 UTC · model grok-4.3
The pith
Equivariance2Inverse reconstructs CT images from limited-angle and blurred scans without ground truth by using rotational invariance.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The authors propose Equivariance2Inverse, which integrates equivariance under rotations into a self-supervised inverse problem framework to jointly address noise modeling inaccuracies and angular undersampling in CT reconstruction.
What carries the argument
The equivariance loss based on rotating the reconstructed object and enforcing consistency, combined with sparsity-promoting regularization in the inverse mapping.
If this is right
- Methods assuming independent pixel noise perform poorly on data affected by scintillator blurring.
- Rotational invariance of the object distribution can be leveraged to reduce artifacts when scanning angles are limited.
- The combined Equivariance2Inverse method shows improved robustness on both real experimental datasets and controlled synthetic tests.
- Self-supervised reconstruction benefits from explicitly accounting for mismatches in the forward imaging model such as blurring.
Where Pith is reading between the lines
- This symmetry-based approach might generalize to other tomographic modalities that exhibit rotational symmetries in their object classes.
- Future work could test the method on clinical datasets with varying degrees of rotational invariance to identify domain-specific limitations.
- Combining the equivariance loss with more detailed models of detector response could yield further gains in reconstruction quality.
Load-bearing premise
The scanned objects come from a distribution that is sufficiently rotationally invariant for the equivariance constraint to guide the reconstruction without adding new errors.
What would settle it
A test set consisting of objects with strong preferred orientations, such as elongated structures all aligned in one direction, where applying the rotational equivariance would degrade the reconstruction quality instead of improving it.
Figures
read the original abstract
Deep learning has shown impressive results in reducing noise and artifacts in X-ray computed tomography (CT) reconstruction. Self-supervised CT reconstruction methods are especially appealing for real-world applications because they require no ground truth training examples. However, these methods involve a simplified X-ray physics model during training, which may make inaccurate assumptions, for example, about scintillator blurring, the scanning geometry, or the distribution of the noise. As a result, they can be less robust to real-world imaging circumstances. In this paper, we review the model assumptions of six recent self-supervised CT reconstruction methods. Based on this, we combined concepts of the Robust Equivariant Imaging and Sparse2Inverse methods in a new self-supervised CT reconstruction method called Equivariance2Inverse that is robust to scintillator blurring and limited-angle data. We benchmarked Equivariance2Inverse and the existing methods on the real-world 2DeteCT dataset and on synthetic data with and without scintillator blurring and a limited-angle scanning geometry. The results of our benchmark show that methods that assume that the noise is pixel-wise independent do not perform well on data with scintillator blurring. Moreover, they show that when the distribution of objects is rotationally invariant, this invariance can be used to reduce artifacts in limited-angle reconstructions.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proposes Equivariance2Inverse, a self-supervised CT reconstruction method formed by combining Robust Equivariant Imaging (to enforce rotational equivariance) with Sparse2Inverse (to handle limited-angle data). It reviews the modeling assumptions of six recent self-supervised methods, then benchmarks the new method together with the others on the real 2DeteCT dataset and on controlled synthetic phantoms with and without scintillator blurring and limited-angle geometries. The central empirical claims are that methods assuming pixel-wise independent noise degrade on blurred data and that, when the object distribution is rotationally invariant, the equivariance loss reduces limited-angle artifacts.
Significance. If the benchmark results are reproducible and the rotational-invariance premise holds for the target domains, the work supplies a practical, self-supervised baseline for real-world CT reconstruction under non-ideal conditions (blurring, limited angles) and supplies a useful comparative study of modeling assumptions. The explicit conditioning of the artifact-reduction claim on rotational invariance of p(x) is a strength that makes the result falsifiable.
major comments (1)
- Abstract and §4 (benchmark description): the claim that rotational invariance 'can be used to reduce artifacts' is load-bearing for the performance advantage of Equivariance2Inverse over the other five methods, yet no quantitative check (e.g., empirical rotational variance of the 2DeteCT or phantom distributions, or an ablation with deliberately orientation-biased data) is reported. Without such a test the equivariance loss could penalize valid structure and introduce new artifacts precisely when the premise fails.
minor comments (2)
- Abstract: no numerical metrics, error bars, or table references are given, which is acceptable for an abstract but makes the magnitude of improvement impossible to gauge from the summary alone.
- Method section: the weighting between the equivariance loss and the sparsity term is listed among the free parameters; a sensitivity plot or recommended default values would improve reproducibility.
Simulated Author's Rebuttal
We thank the referee for the careful review and the insightful major comment. We respond point-by-point below and indicate the revisions we will make.
read point-by-point responses
-
Referee: Abstract and §4 (benchmark description): the claim that rotational invariance 'can be used to reduce artifacts' is load-bearing for the performance advantage of Equivariance2Inverse over the other five methods, yet no quantitative check (e.g., empirical rotational variance of the 2DeteCT or phantom distributions, or an ablation with deliberately orientation-biased data) is reported. Without such a test the equivariance loss could penalize valid structure and introduce new artifacts precisely when the premise fails.
Authors: We agree that a quantitative verification of the rotational-invariance assumption would strengthen the presentation. The manuscript already states the claim conditionally ('when the distribution of objects is rotationally invariant'), but we did not report an explicit metric such as average rotational variance across the 2DeteCT slices or an ablation on orientation-biased phantoms. In the revised manuscript we will add a short subsection in §4 that computes a simple rotational-variance statistic (mean absolute difference between an image and its 90-degree rotations, averaged over the test set) for both the real 2DeteCT data and the synthetic phantoms. We will also note that the observed gains of Equivariance2Inverse remain consistent with the assumption holding reasonably well for the object classes present in these datasets. We do not plan to add a full ablation on deliberately biased data, as that would shift the paper’s focus away from real-world applicability; however, we will briefly discuss the risk that the equivariance loss could penalize valid structure when the premise fails. revision: yes
Circularity Check
No significant circularity; empirical benchmarking of combined self-supervised methods
full rationale
The paper reviews assumptions in prior self-supervised CT methods, proposes Equivariance2Inverse by combining Robust Equivariant Imaging with Sparse2Inverse, and evaluates via benchmarking on real 2DeteCT data plus synthetic cases with/without blurring and limited angles. The rotational invariance of the object distribution is stated as a domain condition under which the equivariance loss can reduce artifacts, not derived from the model equations or fitted to the target result. No load-bearing step reduces by construction to a fitted parameter, self-citation chain, or renamed input; results are external benchmarks against real and synthetic data. This is the common honest finding for a methods-plus-benchmark paper.
Axiom & Free-Parameter Ledger
free parameters (2)
- equivariance loss weight
- sparsity regularization strength
axioms (2)
- domain assumption The forward imaging model (including scintillator blur) is known and differentiable.
- domain assumption Object distribution is approximately rotationally invariant.
Lean theorems connected to this paper
-
IndisputableMonolith/Foundation/AlexanderDuality.leanalexander_duality_circle_linking unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
when the distribution of objects is rotationally invariant, this invariance can be used to reduce artifacts in limited-angle reconstructions
-
IndisputableMonolith/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
Equivariance2Inverse ... robust to scintillator blurring and limited-angle data
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Forward citations
Cited by 1 Pith paper
-
SPLIT: Self-supervised Partitioning for Learned Inversion in Nonlinear Tomography
SPLIT partitions projection data to enforce cross-consistency and measurement fidelity, proving that its self-supervised objective matches supervised training in expectation under mild conditions, with strong results ...
Reference graph
Works this paper leans on
-
[1]
Deep con- volutional neural network for inverse problems in imaging,
K. H. Jin, M. T. McCann, E. Froustey, and M. Unser, “Deep con- volutional neural network for inverse problems in imaging,”IEEE transactions on image processing, vol. 26, no. 9, pp. 4509–4522, 2017
work page 2017
-
[2]
Learned primal-dual reconstruction,
J. Adler and O. ¨Oktem, “Learned primal-dual reconstruction,”IEEE transactions on medical imaging, vol. 37, no. 6, pp. 1322–1332, 2018. 10
work page 2018
-
[3]
Deep learning techniques for inverse problems in imaging,
G. Ongie, A. Jalal, C. A. Metzler, R. G. Baraniuk, A. G. Dimakis, and R. Willett, “Deep learning techniques for inverse problems in imaging,” IEEE Journal on Selected Areas in Information Theory, vol. 1, no. 1, pp. 39–56, 2020
work page 2020
-
[4]
Solving inverse problems in medical imaging with score-based generative models,
Y . Song, L. Shen, L. Xing, and S. Ermon, “Solving inverse problems in medical imaging with score-based generative models,” inInternational Conference on Learning Representations, 2022
work page 2022
-
[5]
Improving diffusion models for inverse problems using manifold constraints,
H. Chung, B. Sim, D. Ryu, and J. C. Ye, “Improving diffusion models for inverse problems using manifold constraints,”Advances in Neural Information Processing Systems, vol. 35, pp. 25 683–25 696, 2022
work page 2022
-
[6]
Diffusion Posterior Sampling for General Noisy Inverse Problems
H. Chung, J. Kim, M. T. Mccann, M. L. Klasky, and J. C. Ye, “Diffusion posterior sampling for general noisy inverse problems,”arXiv preprint arXiv:2209.14687, 2022
work page internal anchor Pith review Pith/arXiv arXiv 2022
-
[7]
Pseudoinverse-guided diffusion models for inverse problems,
J. Song, A. Vahdat, M. Mardani, and J. Kautz, “Pseudoinverse-guided diffusion models for inverse problems,” inInternational Conference on Learning Representations, 2023
work page 2023
-
[8]
Coil: Coordinate-based internal learning for tomographic imaging,
Y . Sun, J. Liu, M. Xie, B. Wohlberg, and U. S. Kamilov, “Coil: Coordinate-based internal learning for tomographic imaging,”IEEE Transactions on Computational Imaging, vol. 7, pp. 1400–1412, 2021
work page 2021
-
[9]
Intratomo: self-supervised learning-based tomography via sinogram synthesis and prediction,
G. Zang, R. Idoughi, R. Li, P. Wonka, and W. Heidrich, “Intratomo: self-supervised learning-based tomography via sinogram synthesis and prediction,” inProceedings of the IEEE/CVF International Conference on Computer Vision, 2021, pp. 1960–1970
work page 2021
-
[10]
Naf: neural attenuation fields for sparse- view cbct reconstruction,
R. Zha, Y . Zhang, and H. Li, “Naf: neural attenuation fields for sparse- view cbct reconstruction,” inInternational Conference on Medical Image Computing and Computer-Assisted Intervention. Springer, 2022, pp. 442–452
work page 2022
-
[11]
Self-supervised coordinate projection network for sparse-view computed tomography,
Q. Wu, R. Feng, H. Wei, J. Yu, and Y . Zhang, “Self-supervised coordinate projection network for sparse-view computed tomography,” IEEE Transactions on Computational Imaging, vol. 9, pp. 517–529, 2023
work page 2023
-
[12]
Noise2inverse: Self-supervised deep convolutional denoising for tomography,
A. A. Hendriksen, D. M. Pelt, and K. J. Batenburg, “Noise2inverse: Self-supervised deep convolutional denoising for tomography,”IEEE Transactions on Computational Imaging, vol. 6, pp. 1320–1335, 2020
work page 2020
-
[13]
D. Chen, J. Tachella, and M. E. Davies, “Robust equivariant imaging: a fully unsupervised framework for learning to image from noisy and partial measurements,” inProceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, 2022, pp. 5647–5656
work page 2022
-
[14]
Proj2proj: self-supervised low- dose ct reconstruction,
M. O. Unal, M. Ertas, and I. Yildirim, “Proj2proj: self-supervised low- dose ct reconstruction,”PeerJ Computer Science, vol. 10, p. e1849, 2024
work page 2024
-
[15]
Sparse2inverse: Self-supervised inversion of sparse-view ct data,
N. Gruber, J. Schwab, E. Gizewski, and M. Haltmeier, “Sparse2inverse: Self-supervised inversion of sparse-view ct data,” 2024. [Online]. Available: https://arxiv.org/abs/2402.16921
-
[16]
Noisier2inverse: Self-supervised learning for image reconstruction with correlated noise,
N. Gruber, J. Schwab, M. Haltmeier, A. Biguri, C. Dlaska, and G. Hwang, “Noisier2inverse: Self-supervised learning for image reconstruction with correlated noise,” 2025. [Online]. Available: https://arxiv.org/abs/2503.19468
-
[17]
P. C. Hansen, J. Jørgensen, and W. R. Lionheart,Computed Tomography: Algorithms, Insight, and Just Enough Theory. SIAM, 2021
work page 2021
-
[18]
Unsure: self-supervised learning with unknown noise level and stein’s unbiased risk estimate,
J. Tachella, M. Davies, and L. Jacques, “Unsure: self-supervised learning with unknown noise level and stein’s unbiased risk estimate,”
-
[19]
UNSURE: Self-supervised learning with Unknown Noise level and Stein’s Unbiased Risk Estimate,
[Online]. Available: https://arxiv.org/abs/2409.01985
-
[20]
A. Wirgin, “The inverse crime,”arXiv preprint math-ph/0401050, 2004
work page internal anchor Pith review Pith/arXiv arXiv 2004
-
[21]
Modelling the physics in the iterative reconstruction for transmission computed tomography,
J. Nuyts, B. De Man, J. A. Fessler, W. Zbijewski, and F. J. Beekman, “Modelling the physics in the iterative reconstruction for transmission computed tomography,”Physics in Medicine & Biology, vol. 58, no. 12, p. R63, 2013
work page 2013
-
[22]
Quantifying the effect of x-ray scattering for data generation in real- time defect detection,
V . Andriiashen, R. van Liere, T. van Leeuwen, and K. J. Batenburg, “Quantifying the effect of x-ray scattering for data generation in real- time defect detection,”Journal of X-ray Science and Technology, vol. 32, no. 4, pp. 1099–1119, 2024
work page 2024
-
[23]
X-ray image generation as a method of performance prediction for real-time inspection: a case study,
——, “X-ray image generation as a method of performance prediction for real-time inspection: a case study,”Journal of Nondestructive Eval- uation, vol. 43, no. 3, p. 79, 2024
work page 2024
-
[24]
M. B. Kiss, S. B. Coban, K. J. Batenburg, T. van Leeuwen, and F. Lucka, “2detect-a large 2d expandable, trainable, experimental computed to- mography dataset for machine learning,”Scientific data, vol. 10, no. 1, p. 576, 2023
work page 2023
-
[25]
Spekpy v2. 0—a software toolkit for modeling x-ray tube spectra,
G. Poludniowski, A. Omar, R. Bujila, and P. Andreo, “Spekpy v2. 0—a software toolkit for modeling x-ray tube spectra,”Medical Physics, vol. 48, no. 7, pp. 3630–3637, 2021
work page 2021
-
[26]
T. Gomi, K. Koshida, T. Miyati, J. Miyagawa, and H. Hirano, “An experimental comparison of flat-panel detector performance for direct and indirect systems (initial experiences and physical evaluation),” Journal of Digital Imaging, vol. 19, pp. 362–370, 2006
work page 2006
-
[27]
A. Howansky, A. Lubinsky, K. Suzuki, S. Ghose, and W. Zhao, “An apparatus and method for directly measuring the depth-dependent gain and spatial resolution of turbid scintillators,”Medical physics, vol. 45, no. 11, pp. 4927–4941, 2018
work page 2018
-
[28]
Emva standard 1288: Standard for characterization of image sensors and cameras,
European Machine Vision Association, “Emva standard 1288: Standard for characterization of image sensors and cameras,” 2021, release 4.0 (Linear)
work page 2021
-
[29]
How does real offset and gain correction affect the dqe in images from x-ray flat detectors?
J.-P. Moy and B. Bosset, “How does real offset and gain correction affect the dqe in images from x-ray flat detectors?” inMedical Imaging 1999: Physics of Medical Imaging, vol. 3659. SPIE, 1999, pp. 90–97
work page 1999
-
[30]
T. M. Buzug,Computed tomography: from photon statistics to modern cone-beam CT. Springer, 2008
work page 2008
-
[31]
R. A. Crowther, D. DeRosier, and A. Klug, “The reconstruction of a three-dimensional structure from projections and its application to electron microscopy,”Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, vol. 317, no. 1530, pp. 319–340, 1970
work page 1970
-
[32]
An inversion formula for cone-beam reconstruction,
H. K. Tuy, “An inversion formula for cone-beam reconstruction,”SIAM Journal on Applied Mathematics, vol. 43, no. 3, pp. 546–552, 1983
work page 1983
-
[33]
B. D. Smith, “Image reconstruction from cone-beam projections: nec- essary and sufficient conditions and reconstruction methods,”IEEE transactions on medical imaging, vol. 4, no. 1, pp. 14–25, 1985
work page 1985
-
[34]
Noise2self: Blind denoising by self- supervision,
J. Batson and L. Royer, “Noise2self: Blind denoising by self- supervision,” inInternational Conference on Machine Learning. PMLR, 2019, pp. 524–533
work page 2019
-
[35]
Noise2void-learning denoising from single noisy images,
A. Krull, T.-O. Buchholz, and F. Jug, “Noise2void-learning denoising from single noisy images,” inProceedings of the IEEE/CVF conference on computer vision and pattern recognition, 2019, pp. 2129–2137
work page 2019
-
[36]
A. A. Hendriksen, M. B ¨uhrer, L. Leone, M. Merlini, N. Vigano, D. M. Pelt, F. Marone, M. Di Michiel, and K. J. Batenburg, “Deep denoising for multi-dimensional synchrotron x-ray tomography without high-quality reference data,”Scientific reports, vol. 11, no. 1, p. 11895, 2021
work page 2021
-
[37]
Scintillator decorrelation for self-supervised x- ray radiograph denoising,
A. Graas and F. Lucka, “Scintillator decorrelation for self-supervised x- ray radiograph denoising,”Measurement Science and Technology, 2025
work page 2025
-
[38]
Estimation of the mean of a multivariate normal distribu- tion,
C. M. Stein, “Estimation of the mean of a multivariate normal distribu- tion,”The annals of Statistics, pp. 1135–1151, 1981
work page 1981
-
[39]
An unbiased risk estimator for image denoising in the presence of mixed poisson– gaussian noise,
Y . Le Montagner, E. D. Angelini, and J.-C. Olivo-Marin, “An unbiased risk estimator for image denoising in the presence of mixed poisson– gaussian noise,”IEEE Transactions on Image processing, vol. 23, no. 3, pp. 1255–1268, 2014
work page 2014
-
[40]
Equivariant imaging: Learning beyond the range space,
D. Chen, J. Tachella, and M. E. Davies, “Equivariant imaging: Learning beyond the range space,” inProceedings of the IEEE/CVF International Conference on Computer Vision, 2021, pp. 4379–4388
work page 2021
-
[41]
Sensing theorems for unsupervised learning in linear inverse problems,
J. Tachella, D. Chen, and M. Davies, “Sensing theorems for unsupervised learning in linear inverse problems,”Journal of Machine Learning Research, vol. 24, no. 39, pp. 1–45, 2023
work page 2023
-
[42]
Foam-like phantoms for comparing tomography algorithms,
D. M. Pelt, A. A. Hendriksen, and K. J. Batenburg, “Foam-like phantoms for comparing tomography algorithms,”Synchrotron Radiation, vol. 29, no. 1, pp. 254–265, 2022
work page 2022
-
[43]
Enabling tomography with low-cost c-arm systems,
M. Abella, C. de Molina, N. Ballesteros, A. Garc ´ıa-Santos, ´A. Mart´ınez, I. Garcia, and M. Desco, “Enabling tomography with low-cost c-arm systems,”PLoS One, vol. 13, no. 9, p. e0203817, 2018
work page 2018
-
[44]
U-net: Convolutional networks for biomedical image segmentation,
O. Ronneberger, P. Fischer, and T. Brox, “U-net: Convolutional networks for biomedical image segmentation,” inInternational Conference on Medical image computing and computer-assisted intervention. Springer, 2015, pp. 234–241
work page 2015
-
[45]
Adam: A method for stochastic optimization,
D. P. Kingma and J. Ba, “Adam: A method for stochastic optimization,”
-
[46]
Adam: A Method for Stochastic Optimization
[Online]. Available: https://arxiv.org/abs/1412.6980
work page internal anchor Pith review Pith/arXiv arXiv
-
[47]
Automatic differentiation in pytorch,
A. Paszke, S. Gross, S. Chintala, G. Chanan, E. Yang, Z. DeVito, Z. Lin, A. Desmaison, L. Antiga, and A. Lerer, “Automatic differentiation in pytorch,” inNIPS-W, 2017
work page 2017
-
[48]
W. Falcon and T. P. L. team, “Pytorch lightning,” 2024. [Online]. Available: https://doi.org/10.5281/zenodo.10779019
-
[49]
Tomosipo: fast, flexible, and convenient 3d tomography for complex scanning geometries in python,
A. A. Hendriksen, D. Schut, W. J. Palenstijn, N. Vigan ´o, J. Kim, D. M. Pelt, T. Van Leeuwen, and K. Joost Batenburg, “Tomosipo: fast, flexible, and convenient 3d tomography for complex scanning geometries in python,”Optics Express, vol. 29, no. 24, pp. 40 494–40 513, 2021
work page 2021
-
[50]
Image quality assessment: from error visibility to structural similarity,
Z. Wang, A. C. Bovik, H. R. Sheikh, and E. P. Simoncelli, “Image quality assessment: from error visibility to structural similarity,”IEEE transactions on image processing, vol. 13, no. 4, pp. 600–612, 2004
work page 2004
-
[51]
An em approach for poisson-gaussian noise modeling,
A. Jezierska, C. Chaux, J.-C. Pesquet, and H. Talbot, “An em approach for poisson-gaussian noise modeling,” in2011 19th European Signal Processing Conference. IEEE, 2011, pp. 2244–2248
work page 2011
-
[52]
Modeling mixed poisson-gaussian noise in statistical image reconstruction for x-ray ct,
Q. Ding, Y . Long, X. Zhang, and J. A. Fessler, “Modeling mixed poisson-gaussian noise in statistical image reconstruction for x-ray ct,” Arbor, vol. 1001, no. 48109, p. 6, 2016. 11
work page 2016
-
[53]
M. Freed, S. Park, and A. Badano, “A fast, angle-dependent, analytical model of csi detector response for optimization of 3d x-ray breast imaging systems,”Medical physics, vol. 37, no. 6Part1, pp. 2593–2605, 2010
work page 2010
-
[54]
Saber: a systems approach to blur estimation and reduction in x-ray imaging,
K. A. Mohan, R. M. Panas, and J. A. Cuadra, “Saber: a systems approach to blur estimation and reduction in x-ray imaging,”IEEE Transactions on Image Processing, vol. 29, pp. 7751–7764, 2020
work page 2020
-
[55]
J. A. Seibert and J. M. Boone, “X-ray imaging physics for nuclear medicine technologists. part 2: X-ray interactions and image formation,” Journal of nuclear medicine technology, vol. 33, no. 1, pp. 3–18, 2005
work page 2005
-
[56]
Calculation of scatter in cone beam ct: Steps towards a virtual tomograph,
A. Malusek, “Calculation of scatter in cone beam ct: Steps towards a virtual tomograph,” Ph.D. dissertation, Link ¨oping University, 2008
work page 2008
-
[57]
Synthetically generated foam ct dataset,
D. E. Schut, “Synthetically generated foam ct dataset,” 2025. [Online]. Available: https://doi.org/10.5281/zenodo.16735632 Dirk Elias Schutis a PhD researcher at the Compu- tational Imaging group of the Centrum Wiskunde & Informatica (CWI) in the Netherlands. His research is part of the UTOPIA project on bringing per product CT imaging for quality control...
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.