{"artifact_id":"L1-033","layer":"L1","title":"Positron Emission Tomography (PET)","domain":"Medical Imaging","sub_domain":"Coincidence-based functional PET","physics_fingerprint":{"L_DAG":3.6,"title":"Positron Emission Tomography (PET)","domain":"Medical Imaging","carrier":"photon","primitives":["L.annihilation_511keV","D.coincidence_detector","L.backproject","int.angular"],"sub_domain":"Coincidence-based functional PET","noise_model":"shot_poisson","problem_class":"linear_inverse","solution_space":"3D_activity_concentration","difficulty_delta":5,"integration_axis":"angular","sensing_mechanism":"pet_coincidence"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 3D activity concentration 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 ~= 14); random_coincidences dominates the stability cliff; scatter and the remaining mismatch parameters contribute higher-order bias terms. Photon-shot-noise-limited (poisson counting) 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":64,"N_LORs":100000000,"SNR_dB":20,"scatter":0.3,"counts_per_LOR":10,"patient_motion":0.0,"random_coincidences":0.1,"attenuation_correction_error":0.0},"input_format":"measurement_only","problem_class":"pet","forward_operator":"pet_forward","epsilon_fn_center":"25.0"},"omega_bounds":{"H":128,"W":128,"Z":[16,512],"N_LORs":[1000000,10000000000],"SNR_dB":[0.0,35.0],"scatter":[0.0,0.5],"counts_per_LOR":[0.1,1000],"patient_motion":[0.0,0.3],"TOF_timing_jitter":[0.0,0.5],"random_coincidences":[0.0,0.5],"attenuation_correction_error":[0.0,0.3]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["pet"],"allowed_omega_dimensions":["H","W","Z","N_LORs","counts_per_LOR","SNR_dB","random_coincidences","scatter","attenuation_correction_error","patient_motion","random_coincidences","scatter","attenuation_correction_error","patient_motion","TOF_timing_jitter"],"allowed_forward_operators":["pet_forward"]},"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":"0xb0fee7279f4fb8f72dc0613a217ce040eac84b6bae89248905ccad2b5e60d5bb","chain_tx_hash":"0x7440ebfb62f7f3d37f47cf9adb30aa59e8710656d8666a930787a10907ff576c","chain_block":41552300}