{"artifact_id":"L1-055","layer":"L1","title":"Magnetic Resonance Elastography (MRE)","domain":"Medical Imaging","sub_domain":"Tissue stiffness via synchronized MR motion encoding","physics_fingerprint":{"L_DAG":4.0,"title":"Magnetic Resonance Elastography (MRE)","domain":"Medical Imaging","carrier":"radio_wave","primitives":["L.rf_excitation","L.motion_encoding_gradient","L.inverse_elasticity","int.temporal"],"sub_domain":"Tissue stiffness via synchronized MR motion encoding","noise_model":"gaussian","problem_class":"nonlinear_inverse","solution_space":"2D_tissue_stiffness","difficulty_delta":5,"integration_axis":"temporal","sensing_mechanism":"mri_motion_encode"},"observable_profile":{"metric":"PSNR_dB","regime":"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.","secondary":"SSIM"},"size_tiers":{"center_spec":{"omega":{"H":256,"W":256,"Z":32,"SNR_dB":20,"f_mech_Hz":60,"motion_artifact":0.0,"wave_reflections":0.0,"tissue_anisotropy":0.0,"inversion_reg_error":0.0},"input_format":"measurement_only","problem_class":"mre","forward_operator":"mre_forward","epsilon_fn_center":"19.0"},"omega_bounds":{"H":64,"W":64,"Z":[8,128],"SNR_dB":[0.0,35.0],"f_mech_Hz":[20,200],"motion_artifact":[0.0,0.3],"wave_reflections":[0.0,0.5],"tissue_anisotropy":[0.0,0.3],"inversion_reg_error":[0.0,0.3]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["mre"],"allowed_omega_dimensions":["H","W","Z","f_mech_Hz","SNR_dB","wave_reflections","tissue_anisotropy","inversion_reg_error","motion_artifact","wave_reflections","tissue_anisotropy","inversion_reg_error","motion_artifact"],"allowed_forward_operators":["mre_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":320,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0x448629572152127fa5dac2a6d337f6a554490bba400bcab8943f3e720ee5811f","chain_tx_hash":"0x5138183ae33ae2e600caf07ff4e4ab2887bce639e099d8434f136f6dd670cf19","chain_block":41553372}