{"artifact_id":"L1-509","layer":"L1","title":"Photoacoustic-Ultrasound Dual-mode Imaging (PAUS)","domain":"Medical Imaging","sub_domain":"Concurrent functional + anatomical imaging via dual-contrast acquisition (multi-physics joint inverse)","physics_fingerprint":{"L_DAG":9.5,"title":"Photoacoustic-Ultrasound Dual-mode Imaging (PAUS)","domain":"Medical Imaging","carrier":"photon_acoustic_dual","primitives":["L.optical_source","L.optical_diffusion","L.beer_lambert","L.thermoelastic_grueneisen","L.acoustic_wave_propagation","L.us_transmit_beam","L.us_pulse_echo","L.transducer_detection_dual","int.spectral_temporal_spatial"],"sub_domain":"Concurrent functional + anatomical imaging via dual-contrast acquisition (multi-physics joint inverse)","noise_model":"gaussian","problem_class":"nonlinear_inverse","solution_space":"4D_dual_contrast_functional_anatomical","difficulty_delta":5,"integration_axis":"spectral_temporal_spatial","sensing_mechanism":"joint_thermoelastic_and_pulse_echo"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of recovered joint state (mu_a, Z, c, rho) is guaranteed within the declared Omega bounds. Uniqueness holds under multi-illumination + multi-wavelength PA acquisition combined with US transmit-receive at adequate SNR; single-wavelength single-illumination PAUS suffers the same multiplicative non-uniqueness as single-wavelength qPAT (excluded from the spec range). Stability is moderately conditioned (kappa_eff ~ 40 after joint model-based reconstruction) — pa_us_synchronization_jitter dominates registration error; fluence_inhomogeneity dominates qPAT-class chromophore bias; acoustic_attenuation dominates US-class deep-tissue contrast; transducer_bandwidth_difference_pa_vs_us contributes a frequency-dependent reconstruction artifact (PA typically lower-frequency band 0.5-10 MHz, US higher 5-20 MHz). Joint Hadamard well-posedness for the coupled qPAT + US Born forward is established by the qPAT references (Bal-Uhlmann 2010, Bal-Ren 2011) plus the dual-mode literature: Niederhauser et al. 2005 (combined OAT/US), Beard 2011 (review), Wang LV 2008 (multiscale photoacoustic), Mehrmohammadi et al. 2013 (PA-US clinical), Park et al. 2017 (PAUS guided interventions).","secondary":"RMSE_per_modality"},"size_tiers":{"center_spec":{"omega":{"H":256,"W":256,"Z":64,"SNR_PA_dB":22,"SNR_US_dB":28,"N_US_modes":2,"voxel_size_mm":0.2,"lambda_range_nm":[700,1064],"N_PA_wavelengths":5,"us_bandwidth_MHz":5.0,"speed_of_sound_mps":1500.0,"acoustic_attenuation":0.0,"fluence_inhomogeneity":0.0,"us_center_frequency_MHz":7.5,"motion_during_acquisition":0.0,"acoustic_speed_heterogeneity":0.0,"pa_us_synchronization_jitter":0.0,"transducer_bandwidth_difference_pa_vs_us":0.0},"input_format":"synchronized_dual_contrast_time_resolved","problem_class":"paus_dual_contrast","forward_operator":"paus_joint_forward","epsilon_fn_center":"26.0"},"omega_bounds":{"H":[128,512],"W":[128,512],"Z":[32,256],"SNR_PA_dB":[5,40],"SNR_US_dB":[5,45],"N_US_modes":[1,5],"voxel_size_mm":[0.05,1.0],"N_PA_wavelengths":[2,16],"us_bandwidth_MHz":[1,20],"speed_of_sound_mps":[1400,1600],"acoustic_attenuation":[0.0,0.4],"fluence_inhomogeneity":[0.0,0.4],"us_center_frequency_MHz":[1,30],"motion_during_acquisition":[0.0,0.3],"acoustic_speed_heterogeneity":[0.0,0.1],"pa_us_synchronization_jitter":[0.0,0.3],"transducer_bandwidth_difference_pa_vs_us":[0.0,0.5]},"epsilon_bounds":{"psnr_db":[8.0,42.0]},"allowed_problem_classes":["paus_dual_contrast","paus_functional_only","paus_anatomical_guided_pa","paus_with_doppler","paus_with_shear_wave"],"allowed_omega_dimensions":["H","W","Z","N_PA_wavelengths","lambda_range_nm","N_US_modes","us_center_frequency_MHz","us_bandwidth_MHz","voxel_size_mm","speed_of_sound_mps","SNR_PA_dB","SNR_US_dB","pa_us_synchronization_jitter","fluence_inhomogeneity","acoustic_speed_heterogeneity","acoustic_attenuation","transducer_bandwidth_difference_pa_vs_us","motion_during_acquisition"],"allowed_forward_operators":["paus_joint_forward","paus_alternating_pa_us_forward","paus_with_shared_tissue_model","paus_with_co_estimated_speed_of_sound"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":280,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0xedc6787d7a57c3ffbe0fcc816d4c1b47dd38ddfa2914b2392b57b48d19033e1d","chain_tx_hash":"0x6d485b3261bc469ae58032e3f62431adb715c465c744d975ddc8ec63b9b20fc0","chain_block":41553387}