arXiv Machine Learning

You Cannot Recover What Was Never Measured: Quantifying the Information Ceiling of Ultra-Low-Field MRI Super-Resolution

arXiv Computer Vision
Sep 23

Uncertainty-Aware 3D Residual Wavelet Diffusion for Ultra Low-Field MRI Super-Resolution

The paper introduces a 3D residual wavelet diffusion model for super‑resolving ultra low‑field MRI scans. By using a lossless wavelet reparameterisation, residual shifting, and domain randomisation, the method fits whole‑brain data on a single GPU, speeds up sampling, and generalises across scanners. It achieves volumetric accuracy comparable to leading regression approaches while producing per‑voxel uncertainty maps that reveal under‑determined regions and preserves disease‑relevant atrophy in cognitively impaired subjects.

By Rui W. Yeow, Millie Beament, Fred Dick, Raha Razin, Martina Bocchetta, David L. Thomas, Henry F. J. Tregidgo, Daniel C. Alexander, James H. Cole
arXiv Computer Vision
Sep 22

Anatomically Faithful Artifact Suppression in SENSE Accelerated Brain MRI

The study introduces ART‑Net, an anatomy‑aware residual attention network designed to refine four‑fold accelerated SENSE brain MRI. In a prospective paired study of 80 participants, ART‑Net achieved the highest peak signal‑to‑noise ratio and structural similarity index among evaluated methods, and it preserved anatomical fidelity with superior Dice coefficients for medial temporal and whole‑brain structures. Radiologist assessments also indicated improved gradient fidelity, regional contrast, and overall structural quality.

By Changjing Chai, Bin Huang, Libo Xu, Jian Zhou, Boyang Pan, Kristen W Yeom, Qiyong Gong, Nan-Jie Gong
arXiv Computer Vision
Sep 3

SliceBridge: context-consistent repair of corrupted slice intervals in T1-weighted MRI

SliceBridge is a new framework for repairing corrupted slice intervals in T1‑weighted MRI by using rectified flow matching conditioned on surrounding intact slices and their relative positions. It enforces through‑plane consistency by coupling slices within the interval through shared noise, flow time, and synchronized sampling, then reinserts the restored interval without altering other slices. In experiments on 9,877 brain MRIs and 581 external subjects, SliceBridge reduced slice‑to‑slice error by 32.9%–41.3% and improved SSIM across interval lengths, while lowering downstream segmentation volume estimation error from 1.95% to 1.05%.

By Jiheng Li, Michael E. Kim, Trent Schwartz, Gaurav Rudravaram, Derek B. Archer, Timothy J. Hohman, the Alzheimer's Disease Neuroimaging Initiative, Lianrui Zuo, Bennett A. Landman
arXiv Computer Vision
Sep 2

Prior-Guided Implicit Neural Representations for Single-Subject Diffusion MRI Super-Resolution

The paper introduces a transfer‑learning framework that pre‑trains an implicit neural representation (INR) on a high‑resolution diffusion MRI template and then adapts it to individual subjects through registration and fine‑tuning. This approach enables native single‑subject super‑resolution, achieving a 4× through‑plane up‑sampling from 5 mm to 1.25 mm on Human Connectome Project data. Compared to a recent baseline, the method reduces NRMSE by 36–49 % and increases FSIM by 24–43 %, while training 6× faster and outperforming other INR‑based techniques on both image quality and domain‑specific metrics.

By Abdulkader Ghandoura, Marsil Zakour, William Consagra, Yogesh Rathi
arXiv Machine Learning
Sep 4

Sharpening the Ensemble: An SSIM-Aligned Residual Refiner for Brain-MRI Inpainting Post-Processing

The paper proposes a lightweight residual refiner that post‑processes the outputs of a two‑model ensemble for brain‑MRI inpainting. By training the refiner with an λ‑weighted combination of α loss and SSIM, the authors achieve a modest but statistically significant SSIM improvement (from 0.8767 to 0.8780 on a held‑out set) without altering MSE. Ablations show that adding a third model or using classical unsharp masking does not yield similar gains, indicating the improvement comes from learned sharpening rather than generic post‑processing.

By Kubilay Ka\u{g}an K\"om\"urc\"u, \.Ilkay \"Oks\"uz