{"artifact_id":"L1-030","layer":"L1","title":"Magnetic Resonance Imaging (MRI) — proton-density / T1 / T2 contrast","domain":"Medical Imaging","sub_domain":"Non-ionizing proton NMR imaging","physics_fingerprint":{"L_DAG":3.6,"title":"Magnetic Resonance Imaging (MRI) — proton-density / T1 / T2 contrast","domain":"Medical Imaging","carrier":"radio_wave","primitives":["L.rf_excitation","L.gradient_encoding","L.fourier_kspace","int.temporal"],"sub_domain":"Non-ionizing proton NMR imaging","noise_model":"gaussian","problem_class":"linear_inverse","solution_space":"3D_proton_density","difficulty_delta":5,"integration_axis":"spatial","sensing_mechanism":"mri_fourier_encoding"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 3D proton density is guaranteed within the declared Omega bounds. Uniqueness holds on the measurement-supported subspace; out-of-support modes are controlled by the declared priors. Stability is moderately conditioned (kappa_eff ~= 15); B0_inhomogeneity dominates the stability cliff; motion and the remaining mismatch parameters contribute higher-order bias terms. Additive gaussian thermal/electronic noise sets the irreducible data-fidelity floor, while mild Tikhonov or analytic inversion is sufficient at the nominal Omega point.","secondary":"SSIM"},"size_tiers":{"center_spec":{"omega":{"H":256,"W":256,"Z":128,"TE_ms":20,"TR_ms":800,"SNR_dB":25,"motion":0.0,"undersampling":1.0,"acceleration_R":1,"B0_inhomogeneity":0.0},"input_format":"measurement_only","problem_class":"mri","forward_operator":"mri_forward","epsilon_fn_center":"30.0"},"omega_bounds":{"H":[64,1024],"W":[64,1024],"Z":[16,1024],"TE_ms":[1,500],"TR_ms":[10,10000],"SNR_dB":[0.0,40.0],"motion":[0.0,0.5],"eddy_currents":[0.0,0.2],"undersampling":[0.0625,1.0],"acceleration_R":[1,16],"B0_inhomogeneity":[0.0,0.3],"coil_sensitivity_drift":[0.0,0.2]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["mri"],"allowed_omega_dimensions":["H","W","Z","TR_ms","TE_ms","acceleration_R","SNR_dB","B0_inhomogeneity","motion","undersampling","B0_inhomogeneity","motion","undersampling","eddy_currents","coil_sensitivity_drift"],"allowed_forward_operators":["mri_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":300,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0xf4c79a28699015645f56a025f6193aa5b705f56cd876ae4da68b6fef8f7b5b41","chain_tx_hash":"0x8b82573487585f10290305930f16657bee0817ca1216945a6624e980a874e103","chain_block":41553358}