{"artifact_id":"L1-057","layer":"L1","title":"Arterial Spin Labeling (ASL) MRI","domain":"Medical Imaging","sub_domain":"Non-contrast brain perfusion via magnetically tagged blood","physics_fingerprint":{"L_DAG":3.5,"title":"Arterial Spin Labeling (ASL) MRI","domain":"Medical Imaging","carrier":"radio_wave","primitives":["L.rf_excitation","L.arterial_labeling_pulse","L.difference_image","int.temporal"],"sub_domain":"Non-contrast brain perfusion via magnetically tagged blood","noise_model":"gaussian","problem_class":"linear_inverse","solution_space":"3D_perfusion_map","difficulty_delta":5,"integration_axis":"temporal","sensing_mechanism":"mri_perfusion"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 3D perfusion 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 ~= 15); arterial_transit_time dominates the stability cliff; labeling_efficiency 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":96,"W":96,"Z":16,"PLD_ms":1800,"SNR_dB":15,"motion":0.0,"labeling_efficiency":0.9,"N_label_control_pairs":30,"arterial_transit_time":1500},"input_format":"measurement_only","problem_class":"asl_mri","forward_operator":"asl_mri_forward","epsilon_fn_center":"14.0"},"omega_bounds":{"H":32,"W":32,"Z":[4,64],"PLD_ms":[500,3500],"SNR_dB":[0.0,30.0],"motion":[0.0,0.5],"labeling_efficiency":[0.5,1.0],"noise_amplification":[0.0,0.3],"N_label_control_pairs":[5,200],"arterial_transit_time":[500,3000]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["asl_mri"],"allowed_omega_dimensions":["H","W","Z","N_label_control_pairs","PLD_ms","SNR_dB","arterial_transit_time","labeling_efficiency","motion","arterial_transit_time","labeling_efficiency","motion","noise_amplification"],"allowed_forward_operators":["asl_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":"0xc3701d48a3f5cc81e706f8c3921d4d727dbb2f58e41d399c1f0b3e2b7ceb28b6","chain_tx_hash":"0xe9c61e1eb30c1788afb6e0fe256c067317875d0f28a83d376a4f051ad0bf50b4","chain_block":41552302}