{
  "abstract": "Purpose: To demonstrate the feasibility of whole-brain multidimensional T1-T2 relaxation imaging on a portable 0.064 T MRI scanner. Methods: A two-dimensional inversion-recovery, fast spin-echo acquisition was used to jointly encode T1 and T2 relaxation. Joint relaxation distributions were reconstructed voxel-wise using marginal-distribution constrained optimization (MADCO). The approach was evaluated in a quantitative relaxation MRI phantom and subsequently applied in vivo in a healthy volunteer. Joint distributions, marginal distributions, distribution-derived measures, and statistical dependencies between the two relaxation dimensions were examined. Results: Phantom joint relaxation estimates showed good overall agreement with mono-exponential relaxation measurements and previously reported values at 0.064 T. The in vivo acquisition provided whole-brain coverage over a broad range of relaxation weightings and tissue contrasts. Reconstructed joint T1-T2 distributions showed spatially organized features across the relaxation space, including broad and overlapping relaxation components that were not fully represented by single-value relaxation maps or by either 1D marginal distribution alone. Selected regions of the joint relaxation space produced component maps with distinct spatial patterns. Statistical analysis further showed a dependence between the two relaxation dimensions, supporting the presence of added information in the joint distribution that is lost when treating T1 and T2 separately. Conclusion: Whole-brain multidimensional T1-T2 relaxation imaging is clinically feasible on a portable 0.064 T MRI scanner. Joint relaxation distributions provide information beyond single-value relaxation mapping and may support further developments of quantitative multidimensional imaging at ultra-low field.",
  "abstract_shown": true,
  "affiliations": [
    "Section on Quantitative Imaging and Tissue Sciences, National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda,"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "name": "E. Wilczynski"
    },
    {
      "name": "K. Najmudeen Magdoom"
    },
    {
      "name": "A. V. Avram"
    },
    {
      "name": "N. H. Williamson"
    },
    {
      "name": "D. Benjamini"
    },
    {
      "name": "S. G. Horovitz"
    },
    {
      "affs": [
        0
      ],
      "name": "P. J. Basser"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ffby4djck4wgv.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.09.04.749459",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.09.04.749459v1.full",
  "id": "ffby4djck4wgv",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.09.04.749459v1",
  "language": null,
  "licence": "CC0-1.0",
  "licence_label": "CC0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/publicdomain/zero/1.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "bioengineering"
    ],
    [
      "openalex",
      "2741|Advanced MRI Techniques and Applications"
    ]
  ],
  "openalex": "W7212046385",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.09.04.749459v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ffby4djck4wgv.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:37Z",
      "native_id": "10.64898/2026.09.04.749459",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.09.04.749459v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:bioengineering",
      "subfield": "systems-synthetic"
    }
  ],
  "title": "Multidimensional T1-T2 Relaxation Imaging In Vivo on a Portable 0.064~T MRI Scanner",
  "title_text": "Multidimensional T1-T2 Relaxation Imaging In Vivo on a Portable 0.064~T MRI Scanner",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:37Z",
  "url": "https://research.draconitic.com/paper/ffby4djck4wgv",
  "venue": "bioRxiv",
  "versions": []
}