{
  "schema_version": "1.0",
  "description": "Reference parameters for HepatoFabric3D synthetic demo and 3D connectivity scoring. Research/educational mapping only; NOT a clinical staging instrument.",
  "disclaimer": "Connectivity index thresholds are illustrative defaults derived for the procedural synthetic generator, not validated against histology. Do not use for diagnosis.",
  "staging_systems": {
    "NASH_CRN": {
      "reference": "Kleiner DE et al. Hepatology 2005 (NASH CRN fibrosis stage F0-F4)",
      "stages": {
        "F0": "No fibrosis",
        "F1": "Perisinusoidal or periportal fibrosis (zone 3 / portal only)",
        "F2": "Perisinusoidal AND portal/periportal fibrosis",
        "F3": "Bridging fibrosis (portal-portal and/or portal-central septa)",
        "F4": "Cirrhosis (regenerative nodules surrounded by fibrous septa)"
      }
    },
    "Ishak": {
      "reference": "Ishak K et al. J Hepatol 1995 (modified HAI fibrosis 0-6)",
      "approx_map_to_NASH_CRN": {
        "0": "F0",
        "1-2": "F1",
        "3": "F2",
        "4": "F3",
        "5-6": "F4"
      }
    }
  },
  "synthetic_stage_params": {
    "F1": {
      "label": "F1 - early periportal/perisinusoidal",
      "n_portal_tracts": 6,
      "n_bridges": 0,
      "fiber_thickness": 1.2,
      "bridge_completeness": 0.0,
      "collagen_area_fraction_target": 0.06,
      "ductular_reaction_intensity": 0.15,
      "steatosis_periportal_bias": 0.55
    },
    "F2": {
      "label": "F2 - portal + perisinusoidal expansion",
      "n_portal_tracts": 7,
      "n_bridges": 2,
      "fiber_thickness": 1.6,
      "bridge_completeness": 0.35,
      "collagen_area_fraction_target": 0.10,
      "ductular_reaction_intensity": 0.35,
      "steatosis_periportal_bias": 0.45
    },
    "F3": {
      "label": "F3 - bridging fibrosis (incomplete septa)",
      "n_portal_tracts": 8,
      "n_bridges": 6,
      "fiber_thickness": 2.0,
      "bridge_completeness": 0.7,
      "collagen_area_fraction_target": 0.16,
      "ductular_reaction_intensity": 0.6,
      "steatosis_periportal_bias": 0.4
    },
    "F4": {
      "label": "F4 - cirrhosis (complete septa, nodules)",
      "n_portal_tracts": 9,
      "n_bridges": 12,
      "fiber_thickness": 2.4,
      "bridge_completeness": 0.95,
      "collagen_area_fraction_target": 0.22,
      "ductular_reaction_intensity": 0.85,
      "steatosis_periportal_bias": 0.35
    }
  },
  "connectivity_index_thresholds": {
    "note": "ConnectivityIndex = (n_bridging_septa_edges / n_portal_nodes) weighted by mean bridge completeness; illustrative bands for the synthetic demo only.",
    "bands": [
      {"band": "minimal",  "min": 0.0,  "max": 0.25, "suggests_stage": "F1"},
      {"band": "low",      "min": 0.25, "max": 0.6,  "suggests_stage": "F2"},
      {"band": "moderate", "min": 0.6,  "max": 1.3,  "suggests_stage": "F3"},
      {"band": "high",     "min": 1.3,  "max": 99.0, "suggests_stage": "F4"}
    ]
  },
  "volume_defaults": {
    "shape_zyx": [48, 96, 96],
    "voxel_size_um": [2.0, 1.0, 1.0],
    "random_seed": 20260601
  }
}