{
  "abstract": "Three-dimensional (3D) reconstruction of bilateral coronary trees (LCA and RCA) from cardiac computed tomography angiography (CCTA) is limited by $64^3$ quantization, territory ambiguity, and sinotubular junction (STJ) ostium drift. We present a canonical $SO(3)$ $(Z_{\\text{IS}}, Y_{\\text{PA}}, X_{\\text{LR}})$ multi-scale representation and Riemannian arborescence framework. First, we map 3D CCTA volumes, centerlines, and thick-stem ostia into $(Z_{\\text{IS}}, Y_{\\text{PA}}, X_{\\text{LR}})$ space, extending a 3D pyramid and tubular decoder with a $128^3 \\to 64^3$ boundary skip, a stop-gradient $128^3$ residual branch, a sub-voxel displacement head $Δ\\hat{\\mathbf{u}}(\\mathbf{x})$, a dual-channel ipsilateral head $(\\mathbf{P}_{\\text{LCA}}, \\mathbf{P}_{\\text{RCA}})$, and a $32^3$ ostium detector. Second, all $327,385$ active parameters ($398,843$ total) are trained in one 30-epoch AdamW loop ($ε= 10^{-8}$) under decoupled L2-SP and aortic-wall consistency. Third, our Riemannian solver couples cylindrical Valsalva-STJ calibration, $128^3$ orifice contact rooting, contralateral inhibition, centripetal pruning, and 4-stage curvature-adaptive normal-plane pullback. On 14 unseen ImageCAS development volumes (28 trees; cases 201--250 isolated), the framework achieves $2.1652 \\pm 0.4686\\text{ mm}$ $\\text{CD}_{\\text{CL}}$ ($\\text{CD}_{\\text{CL}}^{\\text{arc1mm}} = 2.2697 \\pm 0.4863\\text{ mm}$, $p \\le 0.00024$; $57.40\\% / 78.20\\%$ $\\text{F1}@1/2\\text{mm}$; $4.6880 / 4.9298\\text{ mm}$ ostia). Zero-shot evaluation on 50 unseen volumes (Cases 251--300, 100 trees) yields $2.9389 \\pm 1.2785\\text{ mm}$ $\\text{CD}_{\\text{CL}}$ ($p \\le 7.24 \\times 10^{-7}$; ostia $5.1815 / 7.5442\\text{ mm}$), with $2.7696 \\pm 1.1919\\text{ mm}$ pooled $N=64$ $\\text{CD}_{\\text{CL}}$ and $128/128$ trees ($β_0 = 1, β_1 = 0$, $0.0000\\text{ mm}$ detachment).",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.05900",
  "author_total": 2,
  "authors": [
    {
      "name": "Zeyu Jia"
    },
    {
      "name": "Xin Ming"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5d091q51nx2zg.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.05900",
  "fulltext_url": null,
  "id": "5d091q51nx2zg",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.05900",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cs.CV"
    ],
    [
      "arxiv",
      "q-bio.TO"
    ],
    [
      "openalex",
      "1707|Medical Image Segmentation Techniques"
    ]
  ],
  "openalex": "W7220742516",
  "pdf_url": "https://arxiv.org/pdf/2610.05900",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5d091q51nx2zg.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:56Z",
      "native_id": "2610.05900",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.05900"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "arxiv:q-bio.TO",
      "subfield": "physiology"
    }
  ],
  "title": "Tri-Directional Sub-Voxel Displacement and Ipsilateral Territory Decoupling for 3D Bilateral Coronary Artery Tree Reconstruction in Cardiac CT Angiography",
  "title_text": "Tri-Directional Sub-Voxel Displacement and Ipsilateral Territory Decoupling for 3D Bilateral Coronary Artery Tree Reconstruction in Cardiac CT Angiography",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:53Z",
  "url": "https://research.draconitic.com/paper/5d091q51nx2zg",
  "venue": "arXiv",
  "versions": []
}