{"artifact_id":"L1-058","layer":"L1","title":"MR Angiography (time-of-flight / phase-contrast)","domain":"Medical Imaging","sub_domain":"Non-contrast vascular MRI","physics_fingerprint":{"L_DAG":3.4,"title":"MR Angiography (time-of-flight / phase-contrast)","domain":"Medical Imaging","carrier":"radio_wave","primitives":["L.rf_excitation","L.tof_saturation","L.kspace_readout","int.spatial"],"sub_domain":"Non-contrast vascular MRI","noise_model":"gaussian","problem_class":"linear_inverse","solution_space":"3D_vessel_map","difficulty_delta":3,"integration_axis":"spatial","sensing_mechanism":"mri_fourier_encoding"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 3D vessel map 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 ~= 13); inplane_saturation 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":6,"TR_ms":25,"SNR_dB":22,"motion":0.0,"inplane_saturation":0.0,"turbulence_dephasing":0.0},"input_format":"measurement_only","problem_class":"mra","forward_operator":"mra_forward","epsilon_fn_center":"22.0"},"omega_bounds":{"H":128,"W":128,"Z":[32,512],"TE_ms":[3,30],"TR_ms":[10,100],"SNR_dB":[0.0,35.0],"motion":[0.0,0.5],"pulsatility":[0.0,0.3],"inplane_saturation":[0.0,0.5],"turbulence_dephasing":[0.0,0.3]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["mra"],"allowed_omega_dimensions":["H","W","Z","TR_ms","TE_ms","SNR_dB","inplane_saturation","motion","turbulence_dephasing","inplane_saturation","motion","turbulence_dephasing","pulsatility"],"allowed_forward_operators":["mra_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":3,"kappa":260,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0x66f3d02088dd5bd6ecfc0f711984a4bc08eef8f5ae08bd4108ec93e2a4b1df82","chain_tx_hash":"0x92c8b6af4099a0d3253629476b004ea5e35b7f4366649fc9a46e3f6039145ce8","chain_block":41553359}