{"artifact_id":"L1-062","layer":"L1","title":"Contrast-Enhanced Ultrasound (CEUS)","domain":"Medical Imaging","sub_domain":"Microbubble-contrast harmonic ultrasound","physics_fingerprint":{"L_DAG":3.3,"title":"Contrast-Enhanced Ultrasound (CEUS)","domain":"Medical Imaging","carrier":"acoustic","primitives":["L.emit.acoustic_pulse","L.microbubble_oscillate","L.harmonic_separate","int.temporal"],"sub_domain":"Microbubble-contrast harmonic ultrasound","noise_model":"gaussian","problem_class":"nonlinear_inverse","solution_space":"2D_perfusion_map","difficulty_delta":3,"integration_axis":"temporal","sensing_mechanism":"contrast_enhanced_ultrasound"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 2D perfusion map 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 ~= 11); bubble_destruction dominates the stability cliff; nonlinear_tissue_harmonics 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":{"MI":0.1,"f_MHz":3.5,"SNR_dB":22,"N_frames":200,"N_elements":128,"flow_artifacts":0.0,"contrast_washout":0.0,"bubble_destruction":0.0,"nonlinear_tissue_harmonics":0.0},"input_format":"measurement_only","problem_class":"ceus","forward_operator":"ceus_forward","epsilon_fn_center":"22.0"},"omega_bounds":{"MI":[0.05,0.5],"f_MHz":[1,15],"SNR_dB":[0.0,35.0],"N_frames":[30,1000],"N_elements":[32,256],"flow_artifacts":[0.0,0.3],"contrast_washout":[0.0,0.5],"bubble_destruction":[0.0,0.3],"nonlinear_tissue_harmonics":[0.0,0.3]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["ceus"],"allowed_omega_dimensions":["N_elements","f_MHz","MI","N_frames","SNR_dB","bubble_destruction","nonlinear_tissue_harmonics","flow_artifacts","contrast_washout","bubble_destruction","nonlinear_tissue_harmonics","flow_artifacts","contrast_washout"],"allowed_forward_operators":["ceus_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":3,"kappa":220,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0xddf77bb62043675b6608359f2eeb22c27d8ce2e85bcc3ce52a7ee495019eedd7","chain_tx_hash":"0x2d0baaa87ae0de59896f49d719bfbcee5de4f0685ff3adf4e7137930230cadf8","chain_block":41553359}