{
  "assertions": [
    {
      "case": "orthogonal_two_channel_R2",
      "expected": "g near 1",
      "local_g_p95": 1.0,
      "pass": true
    },
    {
      "case": "identical_two_channel_R2",
      "expected": "rank deficient high capped g",
      "local_g_p95": 1000000.0,
      "pass": true
    },
    {
      "case": "global_scale_invariance",
      "expected": "global sensitivity scale should not change g",
      "pass": true,
      "rmsdiff": 7.310578359934718e-17
    }
  ],
  "bart_status": {
    "available": true,
    "returncode": 0,
    "stderr": "",
    "stdout": "v0.9.00"
  },
  "interpretation": [
    "If Mammaria_18_like beats BI_7_like under synthetic complex H-F maps, external tools agree with the intuition that richer H-F sensitivity can improve g-factor.",
    "If the live STEP model still favors BI_7, the issue is the STEP-derived sensitivity surrogate, not the SENSE/g-factor arithmetic alone.",
    "PyGRAPPA and local formula need not match pixel-perfectly, but trends should be interpretable."
  ],
  "purpose": "External PI reference audit using synthetic complex sensitivity maps.",
  "sigpy_status": {
    "available": true,
    "note": "Imported SigPy SenseRecon/EspiritCalib. Full reference recon requires synthetic or measured k-space plus sensitivity maps."
  }
}