K-space Gaussian Representation for Parallel MRI
- URL: http://arxiv.org/abs/2608.00075v2
- Date: Tue, 04 Aug 2026 12:06:57 GMT
- Title: K-space Gaussian Representation for Parallel MRI
- Abstract summary: We propose K-space Gaussian Representation (KGR), the first explicit continuous formulated directly in the native k-space domain.<n>KGR parameterizes the continuous signal using Gabor-Gaussian primitives with shared spatial geometry, yielding a compact representation that naturally preserves inter-coil correlations.<n>These results suggest that explicit continuous parameterization of native k-space provides a principled framework for integrating continuous signal modeling with structured low-rank reconstruction.
- Score: 17.6035099220156
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: Accelerated magnetic resonance imaging (MRI) aims to recover the k-space signal from acquired measurements, where accurate estimation of missing samples is essential for high-fidelity reconstruction. Existing k-space reconstruction methods estimate missing samples through interpolation operators or structure priors defined on discrete sampling grids. Although these formulations effectively exploit local interpolation relationships and global k-space redundancy, they reconstruct only discrete frequency coefficients and therefore do not explicitly model the underlying continuous signal. To overcome this limitation, we propose K-space Gaussian Representation (KGR), the first explicit continuous representation formulated directly in the native k-space domain. Rather than estimating unknown samples on discrete grids, KGR parameterizes the continuous signal using Gabor-Gaussian primitives with shared spatial geometry, yielding a compact representation that naturally preserves inter-coil correlations. Because unconstrained continuous fitting does not necessarily satisfy the intrinsic structural properties of multi-coil signal, the estimated representation is projected onto a low-rank manifold to enforce the algebraic constraints arising from smoothly varying phase and coil redundancy. A frequency-adaptive fitting strategy accommodates the heterogeneous characteristics of different k-space regions. Comprehensive validation across multiple datasets and sampling schemes shows consistent improvements over representative reconstruction baselines in both quantitative metrics and visual quality. These results suggest that explicit continuous parameterization of native k-space provides a principled framework for integrating continuous signal modeling with structured low-rank reconstruction.
Related papers
- Interpretable Activation-Selection Neural Networks for Symbolic Regression of Parameter-Dependent Hamiltonian Eigenvalues [45.88028371034407]
We introduce an activation-selection network (ASN), a differentiable symbolic-regression architecture.<n>Each input node learns a sparse combination of predefined analytical functions, and the trained network can be converted directly into an explicit expression.<n>We apply the ASN to effective three- and four-site spin-chain Hamiltonians relevant to zero-quantum nuclear magnetic resonance.
arXiv Detail & Related papers (2026-08-26T07:45:10Z) - Incremental Aggregation on the Grassmannian for Asynchronous Eigenspace Computation [37.26483427088676]
We study asynchronous optimization for finite-sum eigenspace computation in heterogeneous distributed systems.<n>We propose a Grassmannian incremental aggregation method that refreshes only arriving components and reuses cached gradients.<n> Experiments on serial and distributed PCA demonstrate improved sample efficiency and wall-clock convergence over representative baselines.
arXiv Detail & Related papers (2026-08-05T03:21:38Z) - Semi-Supervised Conditional Generative Learning through Stochastic Interpolation and Sufficient Representations [12.299177496689621]
We propose a semi-supervised framework combining conditional intrinsic with low-dimensional latent representations.<n>RepG decomposes generation into two stages: label-dependent latent sampling and high-dimensional reconstruction.
arXiv Detail & Related papers (2026-07-18T09:21:53Z) - Unified Geometry-Guided ML-FTLE for Tracking Transient Chaos from Scalar Time Series [0.0]
We propose a geometry-guided machine learning framework that unifies predictive trajectory divergence with macroscopic attractor morphology to track abrupt regime shifts.<n>This equation-free framework provides a highly accurate, noise-resilient diagnostic for monitoring structural transitions in complex non-stationary systems.
arXiv Detail & Related papers (2026-06-05T15:22:57Z) - Coverage Analysis of Rydberg Atom Quantum Receiver Arrays: A Stochastic Geometry Approach [55.47164192369501]
Rydberg atomic quantum receivers (RAQRs) offer quantum-limited sensitivity and broadband tunability.<n>In dense deployments, aggregate interference can push atomic transducer out of its small-signal regime.<n>This paper addresses the question by embedding the RAQR front end into a geometry coverage analysis.
arXiv Detail & Related papers (2026-05-22T04:05:13Z) - Spatial Adapter: Structured Spatial Decomposition and Closed-Form Covariance for Frozen Predictors [0.6643390346826856]
We present a parameter-efficient post-hoc layer that equips any frozen first-stage predictor with a structured spatial representation of its residual field.<n>The adapter operates as a cascade second stage on residuals, jointly learning a spatially regularized orthonormal basis and per-sample scores.<n>Because the first-stage parameters are frozen, the adapter does not retrain the backbone; its role is to supply a compressed distributional summary of the residual field.
arXiv Detail & Related papers (2026-05-12T01:29:56Z) - A Mean Curvature Approach to Boundary Detection: Geometric Insights for Unsupervised Learning [52.452902154360565]
We introduce Mean Curvature Boundary Points (MCBP), a novel geometric framework grounded in Geometric Machine Learning.<n>MCBP explicitly models the intrinsic curvature of the data manifold and computes pointwise mean curvature without requiring principled manifold parametrization.<n>Experiments on synthetic and real-world datasets demonstrate that MCBP consistently improves clustering performance.
arXiv Detail & Related papers (2026-05-05T20:19:09Z) - Gabor Primitives for Accelerated Cardiac Cine MRI Reconstruction [18.26499962734637]
We propose Gabor primitives for MRI reconstruction, which each modulating envelope with complex exponential to place its spectral support at an arbitrary k-space location.<n>Experiments show that Gabor primitives consistently outperform compressed sensing, Gaussian primitives, and hash-grid baselines, while providing a compact continuous-resolution representation with physically meaningful parameters.
arXiv Detail & Related papers (2026-03-05T21:15:54Z) - Manifold limit for the training of shallow graph convolutional neural networks [1.2744523252873352]
We study the consistency of the training of shallow graph convolutional neural networks (GCNNs) on proximity graphs of sampled point clouds.<n>We prove $$-convergence of regularized empirical risk minimization functionals and corresponding convergence of their global minimizers.
arXiv Detail & Related papers (2026-01-09T18:59:20Z) - Enforcing Latent Euclidean Geometry in Single-Cell VAEs for Manifold Interpolation [79.27003481818413]
We introduce FlatVI, a training framework that regularises the latent manifold of discrete-likelihood variational autoencoders towards Euclidean geometry.<n>By encouraging straight lines in the latent space to approximate geodesics on the decoded single-cell manifold, FlatVI enhances compatibility with downstream approaches.
arXiv Detail & Related papers (2025-07-15T23:08:14Z) - Last-Iterate Convergence of Adaptive Riemannian Gradient Descent for Equilibrium Computation [52.73824786627612]
This paper establishes new convergence results for textitgeodesic strongly monotone games.<n>Our key result shows that RGD attains last-iterate linear convergence in a textitgeometry-agnostic fashion.<n>Overall, this paper presents the first geometry-agnostic last-iterate convergence analysis for games beyond the Euclidean settings.
arXiv Detail & Related papers (2023-06-29T01:20:44Z) - On the Double Descent of Random Features Models Trained with SGD [78.0918823643911]
We study properties of random features (RF) regression in high dimensions optimized by gradient descent (SGD)
We derive precise non-asymptotic error bounds of RF regression under both constant and adaptive step-size SGD setting.
We observe the double descent phenomenon both theoretically and empirically.
arXiv Detail & Related papers (2021-10-13T17:47:39Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.