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Magnetic Resonance Elastography (MRE) L1-055

Medical ImagingTissue stiffness via synchronized MR motion encodingδ=5 · challengingL_DAG = 4📋 Stub — not mineable
📋

Unclaimed Principle — open for contribution

This Principle is declared in the catalog but has no reference solver, no pinned dataset, and is not registered on-chain. There is no reward pool. Submitting a cert against this Principle today will record the cert for reproducibility but pay zero PWM.

To claim it as a Bounty #7 contribution: open a PR adding (1) a reference solver, (2) ≥1 dataset pinned to IPFS, (3) updates to the L3 manifest with dataset CIDs. After verifier-agent triple-review, the founders' 3-of-5 multisig signs PWMRegistry.register() and the Principle becomes mineable.

Forward model E

Magnetic Resonance Elastography (MRE): mri motion encode produces the measurement through a 4-node primitive DAG L.rf_excitation -> L.motion_encoding_gradient -> L.inverse_elasticity -> int.temporal, with time-integrated exposure and additive Gaussian thermal/electronic noise. Recovery is posed as a non-convex inverse problem that inverts the forward operator to estimate the scene-side 2D tissue stiffness. Difficulty tier delta=5 with effective condition number kappa_eff~16; calibration-level mismatch (wave_reflections, tissue_anisotropy, inversion_reg_error) sets the accuracy floor at the Omega boundary. See the forward_model field for the closed-form imaging equation.

L-DAG

L.rf_excitation -> L.motion_encoding_gradient -> L.inverse_elasticity -> int.temporal
L.rf_excitationL.motion_encoding_gradientL.inverse_elasticityint.temporal

Well-posedness W

Existence:
true
Uniqueness:
true
Stability:
conditional
κ:
320

Existence of the recovered 2D tissue stiffness is guaranteed within the declared Omega bounds. Uniqueness is local rather than global (non-convex landscape); convergence depends on initialisation and priors. Stability is moderately conditioned (kappa_eff ~= 16); wave_reflections dominates the stability cliff; tissue_anisotropy and the remaining mismatch parameters contribute higher-order bias terms. Additive gaussian thermal/electronic noise sets the irreducible data-fidelity floor, while TV / wavelet-sparsity / deep priors stabilise recovery at the ill-conditioned end of Omega.

Solvability C

Solver class:
linear-operator + convex optimisation [Direct-Inversion, Helmholtz-MRE] | linear-operator + deep neural prior [MRE-Net]
Convergence rate q:
2
Complexity:
O(H * W * Z * log(...)) per iteration; learned variants: O(H W Z * F_theta_cost) per forward pass

Specs (0)

No L2 specs registered yet for this principle.